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Non-conductive Gap-Filling Adhesive

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Non-conductive Gap-Filling Adhesive
Posted by RicZ on Monday, November 22, 2021 4:10 PM

I have a kight board from a Walthers Mainline PA which has a broken headlight support (PN 59).  I need to build a replacement support that I can attach to the f=rear of the light support.  What would be a good non-conductive adhesive that will allow me to attach the replacement support to the lights?  In addition, the broken support functions as the LED attach point and has "globs" of solder holding it'.  This creas the need to fill the gap betweeen the new support and the original support.

Would any of the following work:  GOO, epoxy, Weldbond, gap filling ACC, Wood Glue?  Any help is appreciated.


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Posted by selector on Monday, November 22, 2021 5:16 PM

Epoxy for certain.  The five minute kind that has the two syringes, I think it's Lepage, maybe Loctite, can't remember.  Mix really well, two minutes, and forget the 5 minute crap. It will be at least 20 before you can handle the item with confidence.  But it's a really strong product.

Parr clear bond/sealer is really good, a bit more flexible, and of course quite a bit slower to set up, probably 24+ hrs.  

Many would feel confident with Weldbond, but I haven't used it.  I haven't even seen it locally, though I have looked.

Your worst enemy here will be impatience, not the glue you eventually resort to.

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Posted by BigDaddy on Monday, November 22, 2021 9:22 PM

I'm not sure I am reading this correctly, but the caulk I use for laying track is the same caulk I use for affixing  LED's in loco shells.  If I get it wrong and have to reverse wires, I can just peel it off the shell.


COB Potomac & Northern

Shenandoah Valley

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Posted by NVSRR on Tuesday, November 23, 2021 9:09 AM

Not melt glue it will hold but be removable rather easy.   Same with the scenic detail cements.  They dry take, hold the piece but are easy to remove and clean off with water.  


A pessimist sees a dark tunnel

An optimist sees the light at the end of the tunnel

A realist sees a frieght train

An engineer sees three idiots standing on the tracks stairing blankly in space

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Posted by Overmod on Tuesday, November 23, 2021 11:55 AM

I cast a vote for Weldbond, thick as it comes from the maker, put into one of those little squeeze bottles with the long 'hypodermic' applicator tip.

You can pour most of the 'remainder' back in the stock container when done and then flush out the bottle and tip with warm water that has a few drops of dish detergent in it, then rinse.

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Posted by Lastspikemike on Tuesday, November 23, 2021 2:01 PM

Neither PVA nor Weldbond sticks well to plastics. That may or may not be an advantage in this particular situation.

I know Rapido suggests using PVA (they call it white glue) to reattach plastic details to models but it's hard to tell  when Rapido is just joking.

Alyth Yard


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Posted by Southgate 2 on Wednesday, November 24, 2021 5:56 AM

You may be able to use the ol' superglue-baking soda method. Touch the area you want to build up with a dab of super glue on a toothpick or matchstick, then flock it with the soda.  Blow it off, repeat until you have built up the area. It sets instantly with each new layer of soda, but may be somewhat flexible for a couple seconds. 

This works in layers but it does get the baking soda on everything surrounding the area. I blow it off between each new application of soda. The resulting filler becomes very hard, but can be filed nicely. Dont apply the superglue straight from the bottle unless you are deliberately filling large gaps.

You'll still get that superglue white fog on surrounding parts, so don't use on or near items that have to be clear.  Try experimenting on some scrap material to get the hang of it. I've used it to secure LEDs in place, it doesn't conduct current.

It works on metals, plastics (except Delrin, unless you scratch deep grooves in it to give it something to lock into) wood, I've even used it to repair broken off corners of cast plaster walls. Dan

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Posted by Mark R. on Wednesday, November 24, 2021 9:12 AM

My go to for years has been JB Weld Quick. Much stronger than regular epoxy.


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Posted by richhotrain on Wednesday, November 24, 2021 9:53 AM

Mark R.

My go to for years has been JB Weld Quick. Much stronger than regular epoxy.


Agreed. I have used JB Kwik Weld on a variety of projects with great success over the years. You gotta work fast, using small amounts, but the results are amazing.


Alton Junction

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