Home Forums Hunting & Shooting Gunsmithing How to epoxy cross bolts in walnut stock?

Hey guys,

Ive got 3 winchesters with steel cross bolts in the stock. 2 super grades and 1 safari. The cross bolts in all three were finger tight from the factory. Ive tightened them up and used blue lock tight but have been told they are useless unless epoxied into the stock.

a) is this correct
b) how do I go about doing this

Thanks in advance guys

The absolute only good they do is fill the holes drilled for them. Epoxy bedding obviated their need a half-century plus ago.

Now they almost need to be epoxied in place as recoil will hammer the wood around the inlets and loosen it to the point of possibly producing the fulcrum point that breaks the stock.

It is very easy to do and extra clearance is not really needed. Wax or rub release agent on the screws and bolts as well as the edges of the stock around the holes. Then apply your epoxy... it will not take much at all. Let squeeze-out harden a bit before trimming with a razor or scalpel. Take the bolts out after a few hours of curing then reassemble.

This is one of the very few jobs where I have a strong preference for the specific epoxy and feel steelbed has the best set of characteristics in use.

I I strongly disagree with that, they serve a totally different purpose than epoxy bedding.
Recoil impulse causes the stock to to spread and split at the weakest point, ie where the crossbolt goes, and epoxy can't really help with this here because it it is relatively weak in tension, especially in thin layers.
A glued in crossbolt is the best thing you can do for a timber stock.

This is a set and forget job so don't use release on anything.

I do like the steel bed, that is Devcon steel,for this job as it is black, and I like to heat it up a bit after it is mixed with a heat gun after mixing so it flows well.

Work the glue in well, put in the sleeve, screw the nuts up and clean the excess off with a rag soaked in alcohol while it is soft, no cleanup required later

Anytime you heat epoxy you degrade it to one degree or another, depending on how much you heat it. I don't know how much that effects what y'all are doing here, just throwing it out as a general precaution.

I've broken apart pieces of wood by hand that were glued with hot epoxy in an effort to disprove what the West System guys warned us about. After that I took heed to what they said.

Whoa, sorry, but you are way wrong. Epoxy has very high strength in tension and adjuncts can be added if needed to raise that even higher.

You are correct about thin layers not being as strong, but that is a function of their thickness, nothing to do with their relative tensile strength. Further, that thin layer is backed or backing (depending on the point in the pressure cycle) the stock wood.

Many tests have been done on the forces at play here and stockbolts add nothing. Done properly they do not reduce strength

Notice fiberglass stockmakers do not put stockbolts in big kickers... They do not even make the area in question of solid fiberglass.

Absolutely correct! Epoxy 101...

I also do not consider it a set and forget job. I have seen them rusted terribly and in need to inspection and replacement.

Fortunately, epoxy breaks down quickly and easily with heat... I use an old car body soldering gun for the task.

So why not remove the cross bolt entirely and replace with epoxy plug -maybe with chopped fiberglass added. Whatever color you want.. No rust considerations later.

Unless one wants to maintain original looks?

Filled epoxy won't have enough shear strength.

Filled epoxy would have far more sheer strength than the toughest wood... And the real issue is tension, not sheer. Shock resistance is also an issue, but epoxy is stronger than wood there too.

They do look cool when done right...

Since when are cross bolts made of wood?

"Notice fiberglass stockmakers do not put stockbolts in big kickers... They do not even make the area in question of solid fiberglass."

I don't have a dog in this fight but some really good gunmakers (Echols among them) install steel crossbolts in their synthetic stocked rifles.

Obviously cross-bolts are not made of wood... but wood is the material being "protected" by them and it is infrequently subject to splitting when cross-bolts are not used... Adding significant epoxy bedding with glass fibers and epoxy worked into the end grain of the magazine well will absolutely do far more good than cross-bolts.

Aesthetics...

This was the post I had responded to.

Hidden crossbolts for aesthetics? Don't think so.

Did not realize they were hidden... So he installs a bedding block...

By definition, cross-bolts are on the outside to prevent the stock from splitting.

From lab testing on wood I am not in favor of metal bedding blocks, at all... interpolating and extrapolating from those tests leaves me lukewarm at best to using them in fiberglass...

To explain why I do not favor metal bedding blocks or cross-bolts is fairly easy... the metal has a slick surface which is difficult to glue and keep glued because of the differences in thermal expansion rates in the metals versus the glue versus the stock material.

And then the stress from recoil while stressed.

Especially when there are products like Steelbed which gives the benefits of metal without the big thermal expansion differences.

Using an old Sako barreled action with the bedding block, 461 IIRC, and tried all sorts of stuff to make the bedding block remain attached to the bedding for any significant amount of time.

I consider them the answer to the question that either should never be asked or was asked and answered 50 years ago.

It's not a bedding block, it is a set of crossbolts-- the bolts are not exposed to the inlet. A hole is drilled through the stock. That hole is tapped all the way through with a long "airplane tap". A length of all thread is coated with Marine Tex and threaded into the tapped hole. The ends are covered in Marine Tex and the outside is sanded flat and painted over. The all thread avoids the "slick surface" that you describe. The end user will never know it's there but there are two crossbolts in the stock.

I'm the wrong guy to argue the physics of it but I don't think D'Arcy is doing it just for fun, he's not really that kind of guy. A guy who has built as many 458 Lotts as he has over the years know a little about the forces of recoil.

Anything the shoulder can handle, reinforced epoxy is plenty strong enough to handle out there where it all starts. From the standpoint of doing things right threading the hole and then coating it with Marine-Tex, a stiff epoxy compound, and driving them together is a little goofy.

Epoxy will form a perfect match with the threads, stick very well need nothing else. The threads if cut anything like the all-thread will wipe the Marine-Tex off on the way in.

And getting back to the definition of cross-bolts a piece or two of all-thread epoxied into a stock and hidden is not a cross-bolt.

Sitka-

I am confident that you are willing to argue about the definition of a crossbolt as well as the color of the sky for the remainder of 2016, which is fine.

For anyone else interested in a) the problem of a stock cracking through the recoil mortise and b) one proposed solution, this thread does a good job of explaining and visually demonstrating what's going on:

http://forums.accuratereloading.com/eve/forums/a/tpc/f/4711043/m/7211094102?r=1181065102#1181065102

Okay, Argumentum ad Absurdum at that link... The pins there are nothing like the commercial pins the OP is asking about.

Echols is not installing cross-bolts per standard definitions in stockmaking. They are not engaging the recoil lug as is standard and they are not shaped to match the lug... Therefore, the concept of spreading the recoil force over a larger area than the recoil lug by metal-to-metal contact is absent.

The lowest compression value commercial blend steel bed I remember is well over 10,000psi. No shoulder fired rifle is even close to producing the kind of pressure it takes to deform that. No shoulder could handle it if there was that kind of force deliverable.

Making a homogeneous bed is very important in epoxy use subjected to large forces. When it fails it fails at the interfaces.

The splitting forces are built inside the magazine well but are limited by the play in the action screw holes, bottom metal and the action itself.

I am certain Mr. Echols does one hell of a good job, but he is not trying to control traditional splitting with his "cross-bolts".

His comments about untrue recoil lugs is outstanding and his descriptions by photo even better.

More of your posts?

That is funny! Your reading comprehension (a gift by the way) is so poor you do not even understand what you said nor what I said...

I understand well enough to comprehend you don't have a clue about installing a crossbolt that will actually make the stock stronger, even after Woodhits has set you straight.

Typing slowly so you might catch it...

I am willing to bet I can document at least two orders of magnitude more tests to failure on gun stocks than Echols with the purpose of determining what is strongest.

I am certain he found methods that work and has stuck with them. I was testing for ultimate strength...

I have no doubt you can continue to ramble endlessly, but it won't change what I said.
You still seem to have no clue about how crossbolts really work.
(HINT: It's got nothing to do with epoxy)