Stabilizing a crack that doesn't go to an edge?

[DavidC]

I was inletting a barrel into a stock and noticed a bit of flex. I have a roughly 2" crack on the forestock where the front hand would be placed. The crack does not come up to the top of the stock alongside the barrel but runs parallel with the barrel right in the middle of the stock. How can I stabilize this crack?

[Daryl]

Thin or Ultra Thin CA is what I would use. Spread the crack or just wick it in & let it harden, then carry on.

[TommyG]

I had a similar situation last winter with a build.  On morning a crack appeared on the nose of a lock panel that I inlet over a month prior.  Crack ran upward somewhat parallel to the barrel for about an inch and a half.  I ended up flexing it open just a bit and loaded the crack with Titebond 3 using a bent & ground thin paperclip, also employed a can of compressed sterile air(used to clean computers) to help force the glue down into the crack.  Managed to get a small handscrew clamp on it.  Wiped off the excess glue with a damp rag.  No problems since.

[jerrywh]

What bothers me is you can always see that thin dark line where the glue is no matter what. Some say they can hide it but I have never seen one hide it. You can use dark stain to hide it some.

[Stonehouse john]

The toughest part of getting a sound glue joint in cracks is getting enough glue in there to coat the internal surfaces thoroughly.  Sometimes cracks are just too narrow, or too jagged inside, to push the glue in with even the finest magnet-wire (and I've tried some that's human-hair sized, scavenged from various broken electronics around the house). You can try injecting the glue with a small syringe or forcing it in with compressed air as has been mentioned, and that often works, but you're never completely sure how much glue really went in there. 
You said that the crack doesn't run to an edge but does any part of it run through (to the inside of the barrel chanel or into the ramrod hole?).  If so, a trick I use on even the tiniest through-cracks is to position the cracked piece with the crack facing up, lay a generous bead of glue well-covering the crack, and then hold the running shop-vac hose over the crack on the back side.  This method will pull all of the glue you pooled over the crack through to the other side and it completely fills the crack with glue (when you clamp you can tell by how much glue squeezes out).  Really works well.  I've even drilled tiny (1/16") holes on the back side of some pieces where the back doesn't show just to use this method.  Titebond III is a good choice for this method, thinner than yellow glues and a longer open-time for good clamping opportunity.
Not sure if this will be possible for your situation but it works great when you can use it.

John

[DavidC]

John,

I like the idea with the shop vac to draw glue in. I think I'll give that a try but the crack is so fine it may not work. I debate if simply leaving it alone is the best option or if I should widen the back side within the barrel channel and stabilize it.

[flehto]

I've always used super glue for "thin" cracks or open cracks that can be closed and always have stained both sides of the opening before applying the super glue. Seeing super glue doesn't fill gaps, colored epoxy is then used if the gap can't be closed.  Of the 2 repairs, the epoxy is more noticeable due to  the gap and a possible  slight mismatch of color. The super glue crack is "invisible" unless one uses a magnifier.

Had the muzzle  end of the upper forestock crack through the 5/32"  thick  web for 8" and this was repaired w/ super glue and held closed by hand for a minute or 2. Then the muzzle cap was epoxied on. No further work was req'd.......Fred

[Eric Krewson]

I like superglue as well. I bought a Kibler SMR kit second hand, the first owner apparently tried to pull the barrel out of the stock by pulling on the barrel while holding the forestock and cracked the forestock. Apparently he didn't know about holding the gun upside down and tapping upward on the butt stock. The barrel fit was very tight prior to draw filing.

The crack was about 2" long at a 45 degree angle from the top of the forestock. You can see it if you look real hard to the left of the pin and up, the superglue fix came out well.

[jerrywh]

I can see that crack but is you had not told me I don't think I would ever see it.  Looks very good.

[Daryl]

Very hard to see, but visible if you know where to look. If not, good luck.  Hobby Stores that sell trucks and airplane kits
are usually the best places to buy crazy or super glues.  The cyanoacrylate glues they sell come on 4 or more viscosity
grades. Thin is quite thin, but there is also an Ultra thin which will wick into the tightest of cracks & seal them permanently.

[shifty]

     I have used Chair Tite with good results.

[Marcruger]

Fred, there actually IS a super glue that fills cracks and gaps.  I have used it for 30+ years.  It is called "Zap-A-Gap" super glue.  I get the stuff in the green label bottle.  I found it when making plastic models.  It glues parts together and at the same time fills any gaps.  Just sand smooth afterwards.  Great stuff. 

That said, I would stain any surfaces FIRST, as stain will not penetrate into an already glued joint. 

Always test super glue around anything already finished.  The fumes can "fog" and finish and leave it cloudy. 

God Bless,   Marc

[Daryl]

Several viscosities means there are several (4) thicknesses of CA: extra thin, thin, medium & thick.
The medium and thick are the gap filling viscosities.
This works even better if you use the "kicker".

If you use CA to close a cut or wound, do NOT use the kicker.