Pics Added-How to stop a crack in a wooden handguard?

[Pete123]

I have an M39.  The wooden hand guard has a minor crack in it.  What is the best way to keep if from becoming a major crack.

 

I was thinking about something like a thin layer of glue or epoxy or something along those lines on the inside of the hand guard where it won't show.

 

I'm betting that someone on the forum will know more about how to handle this than I do.

 

Any input would be appreciated.

Edited April 24, 2016 by Pete123

[Mike.357]

i'd try drilling a small hole at the end of the crack and put a dowel into the hole.  Use just a small amount of wood glue on the dowel.

Edited April 24, 2016 by Mike.357

[Jonnin]

Wood glue is stronger than most woods when applied correctly.   Drilling the ends of the crack can give strain relief; a very small hole from your smallest bit is often enough for a hairline crack type split.  So I would try drilling both ends (save the drilled out dust) and then glue and if separated, clamp to dry.  Fill in the holes with glue and if visible, mash the dust from the drilling into the glue at the surface to mask it. 

 

You might also look into the root cause of the crack.  Sometimes, its just age, but often in a gun its recoil + a tight fit.  Its often the case that shaving down the wood just a hair at some key point will stop pushing the recoil down the wood and creating the stress that cracked it.  You might also rub the wood down with an appropriate oil if it seems to be cracked due to dryness.  

[VERO1]

You're going to need to inject some glue I to the crack for it to hold. You probably need to wipe the wood down or soak it with lacquer thinner or other degreaser solvent first. I like gorilla glue.

[TrickyNicky]

You're going to need to inject some glue I to the crack for it to hold. You probably need to wipe the wood down or soak it with lacquer thinner or other degreaser solvent first. I like gorilla glue.

 

 

 

Pretty much this IMO. I don't care for gorilla glue though personally.

 

 

Any pics Pete?

[Sidecarist]

Some of the ideas here are good about strain relief and glue.

Gorilla glue should be avoided for spit repair as it expands as it cures.

I repaired a thin shotgun fore end by sanding the inside to get some wood dust I thinned titebond glue and added the dust then rubbed it in the split from the inside. Carful to not get the glue on the outside of the stock. Then as extra insurance I added a very thin piece of fiberglass cloth mixed with the glue dust mix to the inside as there was clearance.

The fiberglass was from model airplane building and was slightly thicker than paper.

As far as I know this repair lasted and its been 10 years+

[Pete123]

Ok, here are pics.  First, let me say that I don't refinish historical stocks anymore.  Before I knew better, I used hot water, a brush and soap to remove the cosmoline and it removed the finish.  I sanded on this stock a long time and came to learn that it was made from wood which can't be made to look good.

 

The hand guard has the original coloring.  I've worked very hard to replicate that on the stock and this is what I could achieve. This has been a pain, has taken a long time

 

The finish is too glossy for a military gun.  Once I put the last coat on it, I have to let it sit for a month and then can put the final finish that mutes the gloss. 

 

Moral of this story:  Don't try to remove cosmoline from wood with hot water, soap and a brush.  

 

Referring to the original reason for the post, you can see the crack on the hand guard at the top left of the picture of the inside.

 

Let me know if the pics change opinions already shared.  

 

Many thanks to all of you.

 

 

 

 

 

[Sidecarist]

It looks like the forward band would prevent too much stress on the crack. If it was me I would carefully reassemble the stock looking for any stress points that might contribute to it growing particularly any twist. Relieve any stress if possible working only on hidden surfaces.

Then I'd measure the crack length as precisely as possible. To keep an eye on any growth.

If you wanted to renforce it use a piece of fine paper or thin 100% cotton cloth soaked in WHITE GLUE as this is reversible with just a bit of water. (Not enough to swell the stock)

[enfield]

I repaired a cracked M1 carbine stock with Elmer's glue. 30 years later you still can't see the repair.

[Djay3]

For stopping a hairline crack in an M1A stock I used one of the CA watery glues (a super glue like agent but very watery) the crack has "disappeared". I used a hobby shop syringe applicator. I used masking tape to limit run off onto the stock's surface. I left it clamped for two days.

Such CA watery gluing agents are available at Woodcrafter retail stores or online. The brand I bought was "Titebond" - Wood Adhesive.

Hope this helps. This stuff is amazingly strong but be careful handling it since it sets up very quickly.

[xtriggerman]

My take on this is you have an easy fix since the crack is open on the end of the hand guard. The only concern with any gun stock crack is has oil and or dirt gotten into it. If so the crack would need to be cleaned or ground out slightly from the inside leaving the visible side alone.
In your case, its always best to try and find a way to clamp the crack "evenly" together for best result but not absolutely necessary in your case. Get your self some G-Flex epoxy. It is relatively fluid like, like honey once mixed and has some of the best "soak in" qualities in a 2 part epoxy. It is an epoxy specially formulated to have expansion/contraction qualities so it can move with the wood during temperature swings and is 100 percent water proof. It's used in acoustic guitar manufacturing. Do not use wood workers glue such as elmers since few of them are waterproof. I used to use Tight Bond exterior but have long since gone to epoxies. In your case where there is no wood missing, the G Flex is the best choice.
Clean the crack as best you can with an air blow gun if u have a compressor and spread the crack a bit to press the epoxy hard into the very end of the crack with your finger. once you get the epoxy all threw the crack, put a wide piece of tap over in on the bottom side, wipe off all excess off the top and use electrical tape over the top like stiches to make sure the crack pulls together as best it can without clamps. The bottom piece of tape will keep epoxy from falling away from any slight gaps.
I have never heard of drilling a hole in wood to stop the growth of a crack. All though it is a common practice on structural metal, wood is a different animal. The major issue with fixing wood cracks is getting the epoxy into the very end of the crack with out disturbing the visible surface. I have a hydraulic injection process explained in one of the "Gun Smithing Kinks" books published by Brownell's that is one of the most effective way of doing it. Good Luck

[Pete123]

Good input - thanks.