Re: Barge Cement


Claus Schlund \(HGM\)
 

Hi Denny,

Thanks for this excellent treatise on the topic - very informative indeed.

I will differ with you on one point - you wrote: "None of the rubbery contact cements that I know of can be dissolved with solvents, and can only be separated mechanically."

Years back I laminated some etched brass car sides onto a plastic core. I used contact cement (probably DAP Weldwood brand) and followed your recommended process, put a thin coat on both and allowed it dry, then positioned everything. Due to reasons too long to explain (nothing to do with the contact cement), the results were less than terrific, and so the project sat untouched in a box for maybe a decade.

After all that time, I decided to try again, and wanted to separate the etched brass sides from the plastic core. I soaked the assembly in Scalecoat Wash-Away (the stuff typically used as a paint remover) for an hour, and everything came apart just fine. I cleaned off the etched brass sides and the plastic core, and was in a good position to correct the problems I ran into first time around.

For the curious, the car looks like this today...

https://c2.staticflickr.com/2/1514/25958482272_b30941bcb6_b.jpg

Claus Schlund

----- Original Message -----
From: "Anspach Denny danspachmd@... [STMFC]" <STMFC@...>
To: "Era Freight Car List Steam" <STMFC@...>
Sent: Saturday, March 26, 2016 9:13 AM
Subject: [STMFC] Re: Barge Cement


Glues and cements: Each and every one has its strong and weak points in our modeling, and there is absolutely no ‘Fits-All’/

Barge: I have been the one over the many years on this list that probably has been the strongest advocate for Barge Cement, and am still dismayed by reports of plastic melting. Barge is a contact cement (like GOO and Pliobond) common to the shoe industry that eventually works only by allowing its solvent to wick off. If gluing two porous surfaces (wood, paper), the glue can wick off into the substrates. If gluing non-porous surfaces, metal, plastic, ceramic, the solvent has nowhere to go- nowhere, except to either stay liquid trapped for months, years, or decades; or….. eat away into any substrate that will allow it, e.g. styrene. The classic distortion and destruction of freight cars floor by weights cemented by glue not allowed to first wick off is a classic example, and a common enough error in application that Accurail -for one- warns not to adhere weights to the floor in application. I learned my lesson very early in this regard with GOO many years ago, so being already forewarned, I do use Barge all the time for my go-to cement when I want instant tackiness, great setting flexibility over quite a few minutes, rubbery ‘give’ and immense sheer strength. There is nothing better for roof running boards- nothing. It is superior to GOO in its delayed setting and ability to be applied in very tiny amounts.

The downsides: The newer ‘blue’ Barge with EPA-mandated reduced volatiles is distinctly more ‘stringy’, sometimes irritatingly so, although still manageable. Those who have the old ‘yellow’ tubes, I am envious… I am tempted sometimes to purchase one of their still-produced commercial ‘yellow’ in cans, but just how to then use it in tiny amounts without huge wastage and the possibilities of a gigantic mess have yet occurred to me.

It seems to be currently only available in large tubes, not the hand ¾ oz. tubes that are so easy in the hand.

None of the rubbery contact cements that I know of can be dissolved with solvents, and can only be separated mechanically.

Failures: Just about each and every failure of these contact glues has occurred because of either poor or inappropriate, unclean, oily, or painted surface preparation or character (e.g. polystyrene). I first used GOO in the fifties, and a jackhammer is commonly used to separate these old glue joints, and when separation is at last achieved, it is often only with parts of the glued surfaces coming long. Barge Cement can be applied in tiny amounts through a small drilled hole in the cap (just large enough to stopper with a specimen T-pin or similar), while GOO simply cannot (I have tried and tried….).

By the way, each and every one of my many valued Accurail cars have their weights secured in place with……..Barge Cement applied only after the surfaces were in full contact mode. Not a single one has had its weight either come loose, nor has the glue distorted the plastic.

Canopy Glue-

I also love this glue, although I use what seems to be the identical Micro Scale product. It’s ability to be cleaned up with water is a tremendous advantage. It is excellent for wood and paper, but holds only weakly for smooth non-porous surfaces. However, an awful lot of what we have to glue does not require great strength of or resistance to sheer forces, and….this glue, once set, can be relatively easily broken down with water or alcohol. I have had no problems with painting, in the very few instances when glue is exposed enough to require it!

I commonly use these two glues together, Barge to tack and hold in place, and Canopy Glue applied for a more definitive hold.

Denny



Sacramento, CA 95864



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Posted by: Anspach Denny <danspachmd@...>
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