Opinion for the court filed by Circuit Judge MacKINNON.
Dissenting opinion filed by Circuit Judge LEVENTHAL.
Upholding the decision of its Administrative Law Judge (ALJ),* the National Labor Relations Board ruled that Local 644 of the United Brotherhood of Carpenters and Joiners of America had violated section 8(b)(4)(ii)(B) of the National Labor Relations Act1 by engaging in a strike designed, through threatening, coercing and restraining certain general contractors, to force them to cease doing business with a subcontractor (Kinnear) because he had not signed an agreement with Local 644.2 The Union appeals this decision, insisting that it sought only to enforce a legitimate work preservation clause against a primary employer. The Board has cross-applied for enforcement of its order, and Morrison Construction Company and Babcock & Wilcox Company, charging parties before the Board, have intervened in these proceedings. Because we agree with the Board that the Union’s acts indicated alternative objectives, not only to preserve traditional work but also to unionize employees outside the unit, we affirm.
I.
In 1970 the Commonwealth Edison Company initiated construction of a multimillion dollar power plant near Pekin, Illinois. Walsh Construction Company was designated general contractor in charge of erection of the plant’s superstructure; Babcock & *5Wilcox Company, Morrison Construction Company, and Eichleay Corporation were also general contractors on the project, respectively responsible for the installation of a steam generator, major piping, and a turbine generator. Each of these contractors employed carpenters and millwrights represented by Local 644, the affiliate of the United Brotherhood of Carpenters and Joiners of America with territorial jurisdiction in Tazewell and Mason Counties, Illinois. Functioning as bargaining representative for all Carpenter Union employees in these counties, Local 644 had negotiated a collective bargaining agreement with the Home Builders Association of Tazewell County, a multiemployer group consisting of all employers “throughout the entire jurisdiction of the union.”3 Walsh was not a member of the Tazewell County Association and had not signed an agreement directly with Local 644. However, there was a contract between Walsh and the Carpenters’ International línion in which Walsh had agreed to recognize the jurisdictional claims of the International and its affiliates for on site work 4 and to abide by the wages, hours and working conditions established or agreed upon by any subordinate of the International in any locality where work of the company is being done. Significantly, the contract with the International also required that Walsh would not subcontract jobsite work within the International’s jurisdiction except to a subcontractor who either held an agreement with the International or one of its affiliates, or who had agreed in writing to be bound by the terms of such an agreement.5
Walsh let a subcontract to Kinnear Corporation for fabrication off site and erection on site of seven roll-up steel doors. Kinnear arrived at the project on September 20, 1971, prepared to erect scaffolding and to install the doors and power mecha*6nisms. A Union job steward noted Kin-near’s arrival and promptly voiced to Walsh’s superintendent his suspicion that Kinnear intended to install the power mechanisms and, with respect to one of the doors, to erect scaffolding over 14 feet high — two tasks allegedly reserved by the Union agreements to carpenters.6 On five different occasions between September 20 and November 8, representatives of Walsh, Kinnear, the Carpenters’ International and Local 644 met in various groups to discuss the assignment of this disputed work, and at almost every turn Walsh’s superintendent assured the Union representatives that the tasks could be performed by carpenters, that “there would be no problem.”7
A sixth meeting was arranged for the afternoon of November 9, but that meeting dissolved when the business agent for the Ironworkers, who represented Kinnear’s employees, made an unscheduled appearance and issued an intractable demand that Kinnear be allowed to perform all tasks associated with installation of the steel doors. Within a half an hour all members of Local 644, those who worked for Walsh and those employed by the other general contractors on the project, walked off the job site. That evening the business agent for Local 644 sent Walsh a telegram demanding arbitration of the no-subcontracting provision of the contract which obtained between those two parties. By the time Walsh received the message the following day — to which he responded that the “dispute had been referred to the Joint Board” —Local 644 had set up a picket line under placards bearing the legend “Walsh Only,” and thus ensued the two-week strike which was the basis of the Board’s section 8(b)(4)(ii)(B) ruling. Despite the “Walsh . Only” placard, all the other general contractors were struck in addition to Walsh.
The strike was both orderly and successful. Picketing took place at “the entry point* for all the construction employees,” and though operating employees of Commonwealth Edison gained access to the site through a separate gate, “none of the carpenters employed by Walsh or the other contractors reported for work, and many employees of other crafts also refused to cross the picket line for varying periods of time.”8 Striking employees did not attempt to solicit support for their effort at the picketed gate.9
The strike concluded on November 24, and the International Unions of the Carpenters and the Ironworkers moved to settle their conflicting jurisdictional claims. They specified in a joint letter dated December 3 that scaffolding over 14 feet should be assigned to carpenters, but no clear resolution emerged from discussion concerning installation of the power mechanisms. The Carpenters’ International representative contended that the Ironworkers’ International had conceded the installation task to carpenters, but Walsh harbored doubts about this concession, insisting it could not change Kinnear’s work assignments without Kinnear’s permission. Apparently to solve this impasse, Kinnear ulti*7mately consented to the assignment of Walsh carpenters to the power mechanism installation.10
Acting on charges filed by Walsh, by the three other general contractors on the project, and by Lord Electric Company (electrical subcontractor for Babcock & Wilcox), the Board’s General Counsel issued a complaint charging Local 644 with violations of sections 8(b)(4)(i) and (ii)(B) because of the Union’s picketing and work stoppage. Following a hearing, the ALJ filed a 16 page decision which included Findings of Fact, Contentions of the Parties, Concluding Findings, Conclusions of Law, and an Order. These point out, inter alia, that the Union contended its strike had “no secondary objective” but rather was part of an attempt to preserve its traditional or “fairly claimable” work and hence had a valid primary motivation; and that the charging parties contended that the Union’s work stoppage and picketing violated sections 8(b)(4)(i) and (ii)(B) because, even if preservation of carpenters’ traditional work was one objective of the work stoppage, another object was enforcement of the contractual restrictions against subcontracting by illegal secondary methods.
In his Concluding Findings, the ALJ stated the criterion by which he would resolve these conflicting claims as follows:
The rule or principle to be applied in determining whether a provision in an agreement between a contractor and a union has a primary objective outside the scope of Section 8(e), or a secondary objective within the scope of that Section, has been variously phrased, but depends essentially on whether the “Union’s objective was preservation of work for [unit] employees, or whether the agreements . . . were tactically calculated to satisfy union objectives elsewhere . . The touchstone is whether the agreement or its maintenance is addressed to the labor relations of the contracting employer vis-a-vis his own employees.” 5 If an object of the provision is to aid union members generally rather than members of the unit, the object is secondary and unlawful.6
(Supp.App.14). He then analyzed the application of National Woodwork, supra, to the instant case, distinguished some of its facts, and — because the Union representatives had constantly referred to such provisions as indicating the objectives of their demands — he considered the subcontracting provisions of the agreement between Walsh and the International which only referred to an agreement with Local 644 as one possible alternative (note 5 supra):
An absolute prohibition of subcontracting is primary in scope, and its violation may be enforced by strike action.
However, a provision which permits an employer to subcontract out on-site construction work only to a subcontractor who will himself agree to be bound by the agreement between the contractor and the union, is an organizational device directed against the subcontractor, designed to preclude a signatory contractor from doing business with a non-signatory subcontractor. The purpose of such a provision is not to protect the work of employees already in the bargaining unit, but to enlarge the coverage of the bargaining unit, by forcing the subcontractor to accept his contractor’s agreement with the Union, thereby affecting his relationship with his own employees who must *8join a union not of their own choosing, and with potential employees who would have to use the Union’s hiring hall.11
The ALJ opinion had also earlier cited additional acts of the Union representatives which, contrary to the allegation made by the dissent, were properly interpreted and relied upon as indicating their secondary objectives12: those representatives, the ALJ stated,
reminded [Walsh’s representative] of the subcontracting clause in the Carpenters [International] agreement with Walsh (Supp.App.10) . . . asked the Kin-near superintendent if his company had a contract with the Carpenters [International] (Supp.App.10) . . . stated that Walsh had an agreement with the Carpenters [International], that the work in dispute was bargaining unit work, and that [the Project Manager of Walsh] would be in violation of the subcontracting provision of the agreement if Kinnear did the work . . . (Supp.App.11), [and 644’s representatives] were concerned whether Kinnear, the subcontractor, had a bargaining agreement with the Carpenters International or some constituent body of that organization. They were demanding in effect that the Carpenters’ jurisdictional claims be observed by Kinnear, and that the work in dispute be assigned to Kinnear employees whom Local 644 would represent.
(Supp.App.15) (emphasis added). This critical finding of fact in the AU’s opinion is also supported by testimony of the Union business agent (Guler) who, after making several ambiguous statements and finally being confronted with an earlier affidavit, testified:
Q. Will you look at page 2 of your affidavit that you have in front of you, General Counsels for identification 10, please? Does that not say at the top of the page, “I told him it would be a violation of the agreement to subcontract that to somebody who didn’t have an agreement with the Carpenters Union”? A. Yes, that’s true.
Q. That is what you said, is it not, at that meeting on September 21st, 1971? A. Yes.
Q. And that was the point you wanted to make, was it not? A. Anything in this statement is true.
(App. 113).
‡ * sfc sf: *
Q. (By Mr. Ziegler) Is it correct, Mr. Guler, you would have been satisfied if Kinnear had done the work using members of the Carpenters Union? A. Using member of the Carpenters Union?
Q. Yes. A. We had no signed agreement. There was no signed agreement with Kinnear.
Q. But if Kinnear had signed one and used members of the Carpenters Union, you would have been satisfied, wouldn’t you? A. If this is what they would have wanted.
Q. If that’s what they wanted to do, that would have been all right with you? A. That would have been okay.
Q. Bécause carpenters would have been doing the work? A. Right.
(App. 111). This testimony, indicating that the objectives of Local 644 were not confined to the claims of its own unit but would have been satisfied if any union carpenter did the work, is buttressed by the facts that Local 644 had no direct contract with Walsh and none whatsoever with Kin-near; that the provision Local 644 sought to enforce in the first instance was embodied in a contract between Walsh and the Carpenters’ International Union; and that a representative of the International was active in the strike negotiations. All these *9facts are found and recited in the opinion of the ALJ, and indicate that Local 644 was not enforcing its own contract but rather was attempting to force Kinnear to abide by a contract between Walsh and the International. These facts are all relevant to the strike objective of Local 644 and they support , the finding that an object of the union was to benefit the International rather than itself.13
The opinion of the ALJ concluded that on the facts of this controversy, “an object of Local 644 was to cause Walsh . to change its method of doing business with Kinnear, the subcontractor, with whom Local 644 had a primary dispute over the assignment of work.”14 The strike thus violated section 8(b)(4)(i) of the Act by inducing employees of the complain-mg parties to cease work in furtherance of a prohibited object, and section 8(b)(4)(ii)(B) by restraining Walsh in furtherance of the same object.
The Board adopted the ALJ’s findings and conclusions and amended them only to include additional section 8(b)(4)(ii)(B) violations stemming from restraint and coercion of Babcock & Wilcox, Morrison, Eichleay, and Lord.15 The Board incorporated by reference the ALJ’s proposed remedy, the issuance of an order that Local 644 cease and desist from the specified unfair labor practices16 and that it take certain affirmative action to rectify the consequences of its unlawful strike, notably the posting of notices affirming the Union’s intent not to engage in the. proscribed inducement and coercion in the future. Local *10644 now petitions this court to review the Board’s decision pursuant to statutory jurisdiction afforded by sections 10(e) and (f) of the Act, 29 U.S.C. § 160(e) and (f).17
II.
This court has made plain its view that “economic action used to enforce a subcontracting clause which implicitly blaeklist[s] all non-union subcontractors violate[s] § 8(b)(4)(ii)(B).” Building & Construction Trades Council v. NLRB, 117 U.S. App.D.C. 239, 240-41, 328 F.2d 540, 541-42 (1964), citing Orange Belt District Council v. NLRB (Orange Belt I), 117 U.S.App.D.C. 233, 328 F.2d 534 (1964); Orange Belt District Council v. NLRB (Orange Belt II), 124 U.S.App.D.C. 349, 365 F.2d 540 (1966); Local 484, Bakery Wagon Drivers v. NLRB, 116 U.S.App.D.C. 87, 321 F.2d 353 (1963); District No. 9, International Association of Machinists v. NLRB, 114 U.S.App.D.C. 287, 315 F.2d 33 (1962); Retail Clerks Union Local 770 v. NLRB, 111 U.S.App.D.C. 246, 296 F.2d 368 (1961). The rationale behind this principle is outlined in Orange Belt I, where Judge Wright, speaking for a division which included Chief Judge Bazelon and Judge Burger (now Chief Justice), state:
Secondary subcontracting clauses in the construction industry are lawful, under the proviso to Section 8(e), and economic force may be used to obtain them notwithstanding Section 8(b)(4)(A) But; under Section 8(b)(4)(B) such secondary clauses may be enforced only through lawsuits, and not through economic action!18
Secondary subcontracting clauses are distinguished from primary provisions by the fact that they are not “ ‘germane to the economic integrity of the principal work unit’ ’’ and do not seek only “ ‘to protect and preserve the work and standards [the union] has bargained for’,” but instead “ ‘extend beyond the [contracting] employer and are aimed really at the union’s difference with another employer’.” Orange Belt I, 117 U.S.App.D.C. at 237, 328 F.2d at 538, citingI Retail Clerks, supra. In this case Local |644’s dispute was with Kinnear (with whom: it had no contract) because Kinnear insisted on assigning work to members of the Ironworkers’ union. Since Kinnear did not have a contract with either Local 644 or the darpenters’ International Union, and thus vas not a primary employer, Local 644’s ictions against Kinnear were clearly secondary in focus. In Building & Con*11struction Trades Council, supra, the same panel as in Orange Belt I made explicit that union signatory clauses — those requiring general contractors to use subcontractors who are “signatory to the agreements of the various construction local unions”19 — by their terms have a secondary focus, and that attempts to secure their enforcement by strikes come within the proscription of section 8(b)(4)(ii)(B).20 That is precisely the situation we have here.
The dissent attempts to make much of the fact that such subcontracting provisions in a collective bargaining agreement are lawful. This is not questioned; the contractor may voluntarily abide by the agreement if he wishes. However, when a union attempts to enforce such agreements by an economic boycott with a secondary objective, it uses unlawful means in an attempt to achieve an otherwise lawful purpose, and runs afoul of the law.21
The clause Local 644 sought to enforce through its picket line bound all members of the Home Builders Association of Tazewell County to subcontract any work within Local 644’s jurisdictional claims only to persons or firms covered by a collective bargaining agreement with Local 644, and to subcontract work within the jurisdiction of the International Union only to parties who had signed an agreement with the International or who were willing to commit themselves in writing to abide by the terms of the agreement between Local 644 and the Home Builders Association. Because Walsh had signed a contract with the International requiring it to abide by the terms of local union agreements, it was bound by this provision. If Walsh assigned to a subcontractor represented by the Ironworkers tasks fairly claimable by Local 644 or the Carpenters International, the assignment was violative of the contract Walsh had negotiated with the International. But, according to the holding of Orange Belt I, Local 644 could not redress its grievance through economic action if the contractual provision on subcontracting it sought to enforce had a secondary focus.
Local 644’s actions had at least two objectives — both unlawful when the Union sought to enforce the contract as written. The Union’s demands sought either to have Kinnear become a party to its collective bargaining agreement with the Home Builders Association, or to have Walsh cease doing business with Kinnear altogether so as to allow International Union members to perform the disputed work. A clause forbidding subcontracting under any circumstances would have achieved the latter result and would undisputably have been dedicated to preserving the economic integrity of the unit, a purpose emphatically approved by the Act.22 But the breadth of the subcontracting limitations in the agreement, to which Union representatives constantly referred as stating their objectives (see text at 7-9 of 175 U.S.App. D.C., at 1142-1144 of 533 F.2d supra and App. Ill) indicates that the demands and objectives of its strike exceeded mere work *12preservation for the unit represented by Local 644. The Union was equally concerned and would have been satisfied, as was decisively indicated by Guler’s quoted testimony, supra at 7-8, of 175 U.S. App.D.C. at 1142-1143 of 533 F.2d, with increasing the number of employees covered by its collective bargaining agreement in order to expand the size of the bargaining unit and augment the power of the International Union. The ease law leaves no doubt that secondary pressures cannot be employed to that end. This finding is supported by substantial evidence and hence it would be in excess of our authority to remand for further consideration as the dissent suggests.
Local 644 seeks support from the Supreme Court’s National Woodwork23 decision and from cases in which this court relied on that opinion to discredit the Board’s use of the right-to-control test of secondary action.24 The Union’s argument is twofold: first, it contends that National Woodwork defined work preservation strikes as primary activity, thus precluding a section 8(b)(4)(B) violation on the facts this case presents. Second, it argues that National Woodwork forbids the use of a per se right-to-control standard in testing the primary focus of an economic action.
National Woodwork, which dealt with a “will not handle” provision, held that a boycott conducted for the sole purpose of preserving traditional unit work and directed at an immediate employer was not violative of section 8(b)(4)(B) in spite of ancillary secondary effects. The Woodwork Court cited the finding of the Trial Examiner that the provision at issue was “not concerned with the nature of the employer with whom the contractor [did] business nor with the employment conditions of other employers or employees.”25 To demonstrate the absence of “union objectives elsewhere,”26 the Court majority also emphasized that the union “refused to hang prefabricated doors whether or not they bore a union label.”27 The clause the boycott in that case sought to enforce guaranteed to union members in the immediate unit the right to fit “blank” doors.
In contrast to National Woodwork, the subcontracting restrictions that the Union demanded be applied here seek either to have the jobsite work performed by a contractor who holds a contract with the Carpenters’ International Union or one of its subordinate unions, or to have that work performed by a contractor who has agreed in writing tq be bound by the terms of a union-drafted agreement or to acquire such traditional work for members of Local 644. Therefore it is obvious that the demands of Local 644 extended beyond preserving traditional work for the unit,28 and *13could have been satisfied if Kinnear’s scaffolding had been erected by any member of the Carpenters’ International Union. The Union’s strike objectives were therefore clearly not limited to preserving work for Local 644 unit members but also included the objective of changing the bargaining representative of the employees of a contractor with whom it did not have a contract. In other words, as the ALJ stated, “an object of Local 644 was to cause Walsh, the neutral general contractor, to change its method of doing business with Kinnear, the subcontractor, with whom Local 644 had a primary dispute over the assignment of work” (Supp.App. 16). This is a classic example of a “union objective elsewhere.” Although Local 644 contends that its action is within the permissible limits of the “on site” building construction exclusion of section 8(e), when Congress enacted that proviso it emphatically indicated that it intended to retain the pre-existing law relating to secondary boycotts in the construction industry:
The committee of conference does not intend that this proviso should be construed so as to change the present state of the law with respect to the validity of this specific type of agreement relating to work to be done at the site of the construction project or to remove the limitations which the present law imposes with respect to such agreements. Picketing to enforce such contracts would be illegal under the Sand Door ease (Local 1976, United Brotherhood of Carpenters v. NLRB, 357 U.S. 93, 78 S.Ct. 1011, 2 L.Ed.2d 1186 (1958)). To the extent that such agreements are legal today under section 8(b)(4) of the National Labor Relations Act, as amended, the proviso would prevent such legality from being affected by section 8(e). The proviso applies only to section 8(e) and therefore leaves unaffected the law developed under section 8(b)(4). The Denver Building Trades case and the Moore Drydock cases would remain in full force and effect. The proviso is not intended to limit, change, or modify the present state of the law with respect to picketing at the site of a construction project.
Labor-Management Reporting and Disclosure Act of 1959 (Landrum-Griffin Act), Conference Report of the U.S. House of Representatives, H.R.Rep.No.1147, 86th Cong., 1st Sess. 39-40 (1959) (report on S. 1555), U.S.Code Cong. & Admin.News 1959, pp. 2318, 2511. See also Northeastern Indiana Building & Construction Trades Council, 148 N.L.R.B. 854, 857-58 (1964), vacated on other grounds, 122 U.S.App.D.C. 220, 352 F.2d 696 (1965); Local 644, Carpen*14ters & Joiners, 200 N.L.R.B. 1056, 1061 (1972); Supp.App. 16.
This court’s decisions following National Woodwork have reiterated that permissible work preservation strikes must be blind to the organizational status of remote employers. In Local 742, Carpenters & Joiners v. NLRB,29 we disapproved exclusive reliance on a per se right-to-control standard to test the primary focus of a work preservation strike, but indicated in unequivocal terms the sort of activity which could be classified as secondary:
The paradigmatic example of secondary activity is a union’s pressuring of its members’ employer to cease dealing with another party simply because the other party does not employ union labor[;] in that case, the union’s objective is addressed strictly to the labor relations of another employer.30
In Local 636, Plumbers & Pipefitters v. NLRB31 a case strikingly similar to Local 742, supra, we noted that a work preservation strike against an immediate employer prompted by disagreement with the labor policies of a remote employer presented “the usual type of ‘secondary’ object.”32 And the majority in our recent decision in Local 638, Plumbers & Pipefitters (Enterprise Association) v. NLRB33 stated that a situation which could taint a valid work preservation objective would be a union’s discrimination “in its work preservation tactics on the basis of the organizational status” of an employer with whom its immediate employer had a contract.34
The principle that a secondary boycott cannot legally be aimed solely at modifying the organizational status of an employer with whom a union has no contract is rudimentary. The complication of this case is that the restriction the Union sought to enforce was in the alternative, and required either that Kinnear change the bargaining representative of those employees who performed the disputed work or that Walsh decline to subcontract the work to employees not represented by Local 644. But it is axiomatic that economic action violates section 8(b)(4)(B) when an object — not necessarily the sole object — of the action is secondary. NLRB v. Denver Building & Construction Trades Council, 341 U.S. 675, 689, 71 S.Ct. 943, 95 L.Ed. 1284 (1951); IBEW v. NLRB, 341 U.S. 694, 700, 71 S.Ct. 954, 95 L.Ed. 1299 (1951); Local 419, Carpet Layers v. NLRB, 151 U.S.App.D.C. 338, 345 n. 13, 467 F.2d 392, 399 n. 13 (1972)35 The mere *15existence of alternative union objectives here does not transform the one objective that is illegal into an “incidental secondary effect,” as the dissent appears to contend. Dissent at 27 of 175 U.S.App.D.C., at 1162 of 533 F.2d. Far from being incidental, the objective in question here was considered substantial enough to be written into the union contract.
Once Walsh had engaged Kinnear to fabricate steel doors off-site and then to erect the requisite scaffolding and install the power mechanisms on-site, the object of the Unions strike was — as its representatives repeatedly stated — logically directed toward changing Kinnear’s organizational status, or toward forcing Kinnear off the site because it would not sign an agreement. The Union’s stated objective could be realized only by one of such methods. But it is illegal to strike for either of such objectives, and so the strike clearly had a secondary object and was illegal despite the fact that Walsh had violated its agreement not to employ subcontractors who had not signed an agreement with Local 644.36 Our *16conclusion in Orange Belt I that a union signatory clause can be enforced only by a lawsuit37 also holds true here, where the signatory provision was joined with a work preservation stipulation, since the alternative purpose of the strike to enforce such subcontracting restriction was — as indicated by the Union demands — the proscribed object of pressuring a remote employer to accept new jurisdictional claims of the Union.
The Union also assails the analysis by which the ALJ reached his conclusions, contending that National Woodwork forbade the use of a “powerless to resolve” (right-to-control) test of secondary conduct.38 The ALJ used the phrase in *17question only once, as he summarized his “Concluding Findings”:
It was Kinnear with whom Local 644 had a primary dispute over which union was to perform the work in dispute, and Walsh was a secondary employer, embroiled in a dispute which it was powerless to resolve except by unilaterally changing the terms of its subcontract with Kinnear or by ceasing to do business with it.39
Since it was essential that he consider all the surrounding circumstances, it was appropriate that he comment on this factual feature of the case. For three reasons, however, the above-quoted sentence does not represent impermissible reliance on a right-to-control standard.
First, it is at best a minor basis of the Board’s decision. The rationale of the opinion the Board adopted was that section 8(b)(4)(B) proscribes economic action taken to enforce the union signatory provisions of the agreement. This proposition was derived from our opinions in Orange Belt I & II, supra, in Bakery Wagon Drivers, supra, and in Local 710, Meat & Highway Drivers v. NLRB, 118 U.S.App.D.C. 287, 294-95, 335 F.2d 709, 716-17 (1964),40 and not from application of the right-to-control test to determine whether Walsh had the right to reassign the disputed tasks to members of Local 644. Following the language of those decisions, the ALJ ruled that the clause the Union sought to enforce was “an organizational device directed against the subcontractor, designed to preclude a signatory contractor from doing business with a non-signatory subcontractor,” to “enlarge the coverage of the bargaining unit” by forcing employees to “join a union not of their own choosing . . . ,”41 The validity of his conclusion that a strike serving these purposes violated section 8(b)(4)(B) is not undermined by his reference to the fact that Walsh was “powerless to resolve” the dispute. It is one circumstance among many that should be considered. When a union strikes an employer for an objective he is powerless to grant it is only common sense to conclude that the union intended by its strike to achieve its objective through other means. No other deduction is reasonable.
Second, even if we were to assume arguendo that this single finding had been a major basis for the Board’s decision, the point that Walsh lacked the means to satisfy the demands of the Union’s strike would not be superfluous to this litigation. In the context of straight work preservation a general contractor’s lack of legal power to reassign disputed work may not be the complete answer to the question whether he is the proper target of a boycott; the fact that he may have contracted away that power, thus binding his own hands, or that he may have retained the means to induce secondary employers to act in a manner consistent with his work preservation understanding may be entitled to some weight. But strikes, such as we have here, to enforce union signatory provisions stand on an altogether different legal footing. That an immediate employer may not be struck to force a remote employer to recognize a different bargaining representative is fundamental to our labor law. Categorically a general contractor lacks the legal power to coerce or induce a change in the labor relations of a subcontractor, regardless of the terms of his collective bargaining agreement with his own employees. Thus, while an employer’s right to control may be merely one item of factual evidence concerning the object of a strike with work preservation aspects, when the strike seeks to enforce a union signatory clause in a contract that evidence points to a significant legal conclusion concerning the use of economic action to alter the labor relations of other parties.42 We are not prohibited, *18as the dissent seeks to have us be, from gleaning a union’s intended object from the clear language of such written provisions.
Third, the Union’s claim that the Board has relied on a per se right-to-control test ignores the scope of the Board’s inquiry into the circumstances of this dispute. Actually, when the entire opinion of the ALJ is read, the contention that the Board relied on a per se test fades into mere unsupported assertion: the ALJ’s conclusion was made only after consideration of all the relevant facts and principles and was not reached automatically or mechanically. His opinion outlines the facts, the law and the reasoning upon which he relied. Although the Board noted that Walsh lacked the power to change Kinnear’s assignment of scaffolding and power mechanism work in compliance with the Union demand, its decision hinged on critical evidence: the Union’s attempt to proselytize employees of a secondary employer, and the object which was implicit in the subcontracting restrictions that the representatives of the Union stated it was seeking to enforce. In our decision in Local 638, Plumbers & Pipefitters (Enterprise Association) v. NLRB, 172 U.S. App.D.C. 225, 521 F.2d 885 (en banc, 1975), cert. granted, 424 U.S. 908, 96 S.Ct. 1101, 47 L.Ed.2d 311, 44 U.S.L.W. 3471 (U.S. Feb. 23, 1976) (No. 75-777), we ordered the Board to reconsider a ruling predicated on a right-to-control determination, and offered the specific suggestion that “such a reconsideration might challenge the Board’s assumption that the union was not in fact attempting to organize . . . employees [of a remote employer].”43 Consistent with numerous decisions of this court,44 the Enterprise majority recognized that evidence of such an organizational purpose would taint an otherwise valid work preservation strike. When the Board has found within the plain terms of the collective bargaining agreement, and in the Union’s stated objective to enforce the dictates of that agreement, irrefutable proof that the Union’s strike has an object proscribed by section 8(b)(4)(B), a remand for further consideration based on the speculation that there were other surrounding circumstances which the Union had not presented previously would be a meaningless elevation of form over substance not mandated by the National Woodwork decision.
in.
The Union advances the ostensibly exculpatory argument that the subcontracting provision it sought to enforce was actually far less restrictive of its employer’s options than an absolute ban on subcontracting: Walsh was given latitude in se*19lecting the employees to perform particular tasks, limited only by his agreement to employ union signatory labor. But the Union cannot defend against the charge that it has exerted unlawful secondary pressures by insisting that it has been solicitous of the employer with whom its International union has a collective bargaining agreement. The Act allows a broad range of activity designed to pressure primary employers into granting concessions and honoring commitments, but categorically forbids economic action undertaken for the purpose of pressuring secondary employers. This principle underlies the passage from Orange Belt I quoted above45: a union may strike to obtain a construction subcontracting clause which exacts a signatory obligation from secondary employers, since the effort to gain this concession is directed only against the union’s immediate employer, but it may not strike to enforce the provision, for to do so is to force secondary employers to alter their union status or to “cease doing business” with the struck primary altogether. In the context of this ease, Local 644’s attempt to compel Walsh to abide by the subcontracting restrictions had the object of forcing Kinnear off the site unless it agreed to the Union’s jurisdictional claims. The terms of section 8(b)(4)(ii)(B) clearly proscribe this action, and the language of section 8(e) does not validate it.46
The Union concedes that economic action taken in support of a demand that a general contractor “replace [a] non-signatory (non-union) subcontractor with a signatory (union) subcontractor” represents a “classic secondary boycott” with an “illegal cease doing business objective,”47 but attempts to justify its strike as unrelated to Kinnear’s signatory status. By the Union’s accounts, “[n]o demand was made upon Kinnear. Nothing was sought of Kinnear.”48 The ALJ considered and rejected this argument in his decision:
[I]t is made to appear as if Local 644 merely wanted Walsh to honor a commitment to use its own carpenter employees for work within the Carpenters’ claimed jurisdiction, whereas Local 644 was in fact insisting that Kinnear assign the erection of scaffolding over 14 feet, and the installation of the door mechanisms to its members generally rather than to members of the Ironworkers Union.49
The ALJ discarded the Union’s argument because its portrayal of the objects of its strike was utterly unrealistic. It must also be remembered that Local 644 was necessarily relying, in the first instance, on the agreement between Walsh and the International Union and not any agreement to which it was a direct party. The dispute between Walsh and the Union could have been resolved only if Walsh had induced Kinnear to observe the carpenters’ jurisdictional claims by assigning the disputed work to members of the Carpenters’ International Union (including but not limited to members of Local 644). The Union’s claim that a strike to these ends did not constitute a “demand” on Kinnear flies in the face of reason, the evidence, and the decisions of the ALJ and the Board.
As an attempted third justification of its action, the Union insists it sought only to enforce an arbitration clause in its agreement with the Home Builders Association, not to force Kinnear to become a signatory or quit the project. Even if it were conceded thát the Union sought arbi*20tration, that would not alter its objectives in striking or validate an otherwise illegal secondary boycott. The facts also belie the Union’s contentions that it was only attempting to secure arbitration of its demands. The prospect of arbitration was raised for the first time in the telegram the Union sent Walsh on the evening of November 9, after all members of Local 644 had walked off the jobsite.50 Walsh received the telegram on November 10, presumably some time after 7:10 A.M., when Local 644’s picket line was set up.51 Thus the fact that the Union’s placards- charged Walsh with a “Refusal to Arbitrate” as well as a “Violation of Contract" does not disguise the true cause of its strike, i. e., the failure of Walsh and Kinnear between September 20 and November 9 to comply with the subcontracting restrictions of the Walsh agreement with the International. Moreover, Walsh did not steadfastly refuse to arbitrate, as the Union suggests; instead, through a telegram sent at 5:15 P.M. on November 9, well before it received the Union’s telegram demanding arbitration, Walsh requested the intervention of the National Joint Board for the Settlement of Jurisdictional Disputes, an arbitral forum which could involve and bind both the Carpenters and the Ironworkers. Resolution of the dispute by this body would have alleviated Walsh’s justifiable fear “that an arbitrator’s ruling limited to Carpenters and its subcontracting clause would not prevent Ironworkers from continuing to claim the work, which could lead to a walkout by Ironworkers and renewed pressure from Carpenters.”52
Finally, the Union points to the fungibility of carpenters on the project as evidence that its pressure was directed only toward parties in the unit, and solely for the purpose of preserving its economic integrity. As carpenters were laid off by one employer, they went into a pool composed of all carpenters on the project, to be rehired on a rotating basis by another employer. If the Union intends to suggest that the general contractor and his subcontractors on a construction site constitute a single unit, that “employees of one [are ipso facto] employees of the other,” then it has ignored the holding of NLRB v. Denver Building & Construction Trades Council, 341 U.S. 675, 690, 71 S.Ct. 943, 952, 95 L.Ed. 1284 (1951), to the contrary. Rotation among carpenters did not involve ironworkers and cannot be deemed to have included them in Local 644’s unit. Once Kinnear was awarded the task of installing the seven steel doors, Walsh could not compel Kin-near to use any carpenters to work on the tall scaffolding and the power mechanisms, regardless of their immediate employer, without pressuring the Ironworkers’ Union to accept Local 644’s jurisdictional claims. We have amply documented the impermissibility of that purpose.
Conclusion
Both the ALJ and the Board determined that Local 644 struck with the object of enforcing the union signatory aspect of the subcontracting restrictions it had negotiated with the Home Builders Association. These became applicable, and only as one of several alternatives, because of a limited provision of Walsh’s agreement with the International. The stated and logical purpose of the Union’s economic action was to compel ironworkers and Kinnear to abide by the carpenters’ jurisdictional claims. The fact that the strike was successful, that it led to the capitulation of Kinnear and the Ironworkers’' Union, does not justify the Union’s action. We perceive no reason to deviate from our longstanding position that a union violates section 8(b)(4)(B) when it strikes its immediate employer to ensure *21that he contracts only with parties signatory to the union’s collective bargaining agreement. Accordingly, since there is substantial evidence on the record as a whole supporting the factual findings of the Board, we are not at liberty (as the dissent suggests at page 25 of 175 U.S.App.D.C., at page 1160 of 533 F.2d) to remand the case for what it speculates might be different findings.53 The decision of the Board is therefore
Affirmed.