doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Recommended adhesive for crack repair?

IF you use cyanoacrylate, think about using an accelerator to strengthen the bond. Check with a local R/C airplane or model railroad store for the good stuff. Accelerator is usually aerosol and you spray it on the joint after wicking in the glue.

If you want to use epoxy, think about Liquid Wood from Abatron. It is designed to wick into the wood fibers and you can thin it with xylene, no heat required. Wonderful stuff for repairs and restoration.

Yes, use super glue. It sounds hokey, but I use it all the time. And it works great.
For a crack that you can't really get into fully, the liquid works well. Just open it up as much as you can and flow it in.

Of course, everything works better when the wood is clean and dry.

Thanks All. I appreciate the suggestions. I've used accelerator's before. I don't remember for what project exactly; I think it was some sort of music instrument repair.

IMO, any CA is not the best choice for MOST stock repairs. It doesn't like to "flex" and as the wood expands/contracts over time and recoil, it can separate.

Many, many different kinds of epoxy that IMO, are better for this application.

With a little heat and and compressed air, you get get epoxy to flow anywhere you need it to go.

You can often get runny acraglass in with a shot needle from veterinary supply. Expoxy should hold up better to recoil IMO. It can also be thinned. Pins can also be placed from invisible angles if needed in lots of cases. Steve

I have repaired and rebedded a couple of rifles that had originally were repaired with what I believe was Acraglas. Time does not seem to be friendly to that formula. Acraglas seems to get 'brittle' over time. It is easy to use, and DOES work.

So I switched to a marine epoxy, as those formulas are designed to deal with hull flex and movement. I don't know if it will last better than Acraglas over decades, but I hope to never find out.

I use this product: http://www.amazon.com/s/?ie=UTF8&key..._sl_jpvplb1k3_e

Good working time and easily thinned by heating the stock with a lamp before applying the epoxy.

I like the idea of marine epoxy. I found some wood specific super glue just down the street, so I gave it a try. Seems to have worked very well for the time being. Hope it holds up.

Thank you all for being generous with your suggestions and shared experience.

Cyanoacrylate glues are very strong in tension, but weaker in shear. For clean wood, Titebond II wood glue is tough to beat, but you'll need compressed air to force it into a crack. I tested various wood glues several years ago on small blocks of planed black walnut. The Titebond II was stronger than the wood when I attempted to break it apart after a couple weeks, as was Acraglas, and a Marine Epoxy. A polyurethane glue I tried was also very strong and gave a glue joint that was hard to detect, but it was messy to work with and affected finishing of the surrounding wood if you couldn't sand off what squeezed out of the joint. I have read that polyurethane glue works good when there may be traces of oil left in the wood.

The Titebond II gave me the most invisible glue joint when finished with over half a dozen various finishes including Tung oil, Permalyn, Spar Varnish, Oil Modified Urethane, Polyurethane, Watco Danish Oil, Tru-Oil, etc. With careful grain and pore matching on my test blocks, it was almost impossible to detect a closely fitted joint. For a cracked stock with no missing wood, and careful clamping, you can make a repair so invisible, no-one will ever know it was broken. This is what I was looking for. Many repaired stocks may be strong, but the glue joint sticks out like a sore thumb. I did not even test any of the Super Glues because I knew they were not ideally suited for the shear and flexing type of forces required for a lasting bond in a gunstock.

Finally.

A man who know what the heck he's talking about.

Refreshing.

All epoxies will be brittle if they are not mixed in the proper ratios. The rule of thumb is that the less catalyst you use, the more flexible the joint will be when it cures. Hotter batches cure faster, get harder, and will be more brittle as they age. Cooler batches may take a long time to reach full bond strength, but will generally be better in the long run.



Warming the stock is a double edged sword. It will thin the material and allow better penetration and wicking, but it also accelerates the cure and can lead to the brittleness problem down the road. There are various grades of epoxy, with wide variations in quality, but all generally behave in the same way with heat and cure ratios. If you really need to thin epoxy and want to avoid heat, thin the epoxy with xylene/xylol and be prepared to clean off any squeeze-out immediately.