concurring in part and dissenting in part.
I concur with the majority’s holding that the district court did not clearly err in concluding that the Kentucky State District Council of Carpenters, AFL-CIO (the Union) violated § 8(b)(4) of the National Labor Relations Act (NLRA), but write separately to express my view with regard to the proper scope of that holding. In addition, I respectfully dissent in part from the majority’s calculation of the damages owed F.A. Wilhelm Construction Company, Inc. (Wilhelm) because of. the Union’s § 8(b)(4) violation.
The district court found that the Union intended to conduct a secondary boycott when it asked all of its members, including those employed by Wilhelm, to help staff a picket line set up against two nonunion employers, Dant Clayton Company (Dant) and Dailey Seating Company (Dailey). Because I believe this issue to be a close call, I agree with the majority that the district court’s finding is not clearly erroneous. I write separately, however, to express my concern that the majority’s holding on this issue might be construed as creating a per se rule that a labor union necessarily intends to conduct a secondary boycott anytime that it asks its members to assist in staffing a picket line. In my view, drawing such an inference would not always be justified, as, for example, where a union makes clear that it seeks the assistance of its members who work for secondary employers only when those employees are off-duty.
The Union in the present case, however, did not clarify its intent to limit the picket call 'to off-duty employees. It instead made an unconditional request that all of its members help staff the picket line being organized against Dant and Dailey. Moreover, the Union distributed a card to its members less than a month before the picket line began that stated “GOOD UNION BUILDING TRADESMEN do not work behind banners even with 4 gates,” thereby implicitly calling on its members who worked for secondary employers, to join any strike that might take place at the construction site. The card also stated that the Union could not advise its members what to do, but any member reading the card would likely interpret its overall effect as “a wink and a nod” to join the strike if and when it was called. Accordingly, I am not left with the “definite and firm conviction” that the district court erred in inferring from these facts that the Union intended to conduct a secondary boycott in violation of § 8(b)(4). Sanford v. Harvard Indus., Inc., 262 F.3d 590, 595 (6th Cir.2001) (noting that a factual finding is clearly erroneous only if the reviewing court is “left with the definite and firm conviction that a mistake has been committed”).
I am convinced, however, that the district court erred in awarding damages to Wilhelm for the lost use of the equipment that it had rented for the construction project. The majority reaches the opposite conclusion, reasoning that the district court properly awarded Wilhelm a prorated amount of the monthly rental cost of the equipment that sat idle. But Wilhelm never offered proof that it was required to pay a penny more in rental fees because of the strike-induced delay in construction. The record, moreover, provides no support *944for the majority’s assertion that this equipment “likely could have been used on another job site.” Maj. Op. at 942. Furthermore, as opposed to its own equipment, Wilhelm neither incurred depreciation costs nor lost potential rental, income as a result of the borrowed equipment sitting idle during the six-and-one-half days of the strike.
A damage award must be based upon more than speculation. See NLRB. v. Ferguson Elec. Co., Inc., 242 F.3d 426, 431 (2d Cir.2001) (“A backpay award must be sufficiently tailored to remedy only the actual consequences of an unfair labor practice, and should not address purely speculative damages.”). Absent evidence that Wilhelm suffered an actual loss as a result of not using the rented equipment during the strike, the award of damages approved by the majority appears to be grounded in speculation and potentially provides Wilhelm with a windfall at the expense of the Union. I therefore disagree with the majority’s conclusion that Wilhelm established its right to recover damages based upon the lost use of the rented equipment. On the other hand, I have no quarrel with the authorities relied upon by the majority in awarding Wilhelm damages for the lost use of its own equipment.
In sum, I would affirm the district court’s conclusion that the Union violated § 8(b)(4) of the NLRA, but would remand for a revised calculation of damages because of Wilhelm’s failure to adequately prove an actual loss resulting from the rented equipment sitting idle during the strike.