Bedding thickness?
- Thread starter TrxR
- Start date
I apply it approx 1/8" thick in most areas around the receiver & barrel, maybe a little more in some of the deeper inletted areas. All the excess epoxy gets squeezed out anyways. Just use enough so that you make contact between the stock and the receiver/barrel areas.
I like to keep the bedding as thin as possible. Especially on stocks with metal cross bolts or aluminum frames inletted into them.
There isn't any type of bedding epoxy made that's as strong and hard as metal and that includes aluminum. I agree with guntech on skim coating the pillars.
I like to bed the pillars tight against the receiver on the first application of epoxy. After a couple of days of curing, I like to go back and skim coat the whole job again. This covers up a lot of sins that can easily happen. Before the final skim coat, which is often extremely thin and applied with a small brush, I will also lightly sand the bedding for better adherence.
My main reason for going back to skim coat is that epoxy will shrink after a few days. I don't like to have to force my receivers out of or back into the stocks.
There isn't any type of bedding epoxy made that's as strong and hard as metal and that includes aluminum. I agree with guntech on skim coating the pillars.
I like to bed the pillars tight against the receiver on the first application of epoxy. After a couple of days of curing, I like to go back and skim coat the whole job again. This covers up a lot of sins that can easily happen. Before the final skim coat, which is often extremely thin and applied with a small brush, I will also lightly sand the bedding for better adherence.
My main reason for going back to skim coat is that epoxy will shrink after a few days. I don't like to have to force my receivers out of or back into the stocks.
Not all epoxies shrink on curing... one of the reasons I use Brownell's Acra-glas products is it is formulated to not change through the curing process... and I always tape clearance of the front, sides and bottom of the recoil lug.
You're right on Brownell's Acra Glas.
I have a rather large stash of Titanium Putty, which was surplus after the company I worked for shut down. They were going to toss it and I rescued it.
I like it because it's about the hardest epoxy I can find. It does however have about a 2% shrinkage problem after 48 hours or so. I use Acra Glas for a skim coat on the final finish. Tape is nice for clearance and I use it on my hunting rifles. For the precision rifles, I use a Krylon Mold Release Agent.
We prefer to blend our own bedding compound using aerospace epoxy resin as a base and several different fill materials. One can tailor the viscosity to suit the bedding, can also tailor physical properties of the bedding material to suit the application of the rifle. Even choose the hardener to suit requirement/temper possibilities. Shrinkage can be very low due to high fill grade of solid materials achieved by using different sized and shaped fillers.
The depth or bedding thickness depends on the stock, bit like foundation of a house. Build on sand and you need thicker foundation. Some composite stocks have very soft fill materials, much softer than the bedding material meaning one can bed deeper. If the stock material is stronger/harder than the bedding material one should try skim bedding as mentioned before with alu stocks or high quality composite stocks.
edi
The depth or bedding thickness depends on the stock, bit like foundation of a house. Build on sand and you need thicker foundation. Some composite stocks have very soft fill materials, much softer than the bedding material meaning one can bed deeper. If the stock material is stronger/harder than the bedding material one should try skim bedding as mentioned before with alu stocks or high quality composite stocks.
edi
I would try a bedding with around 2-3mm wall section.
slightly off topic.... I hope nobody minds.
Bedding a wooden stock is of course a good opportunity to increase strength especially across the fibre direction to avoid stock splitting. One can also use fibre bundles to transfer the recoil from the recoil lug into the stock as well as strengthening parts of the forend. All the bedding and reinforcement would be hidden by the action. As mentioned going the filled resin route has also the advantage to use some unfilled resin with fibre bundles put in place under the bedding all in one go. One can go as far as milling small channels in the stock to run soaked say carbon bundles (rovings) making the stock or inlet area much more rigid.
Did these years ago for my own CZ223 rifle and a friends Ruger. In the meantime I only work with carbon composite stocks.
the rovings on the ruger running under the bedding to the root of the forend. Where the action screw hole is one can see rovings going side to side taking the role of a crosss bolt.
Ruger bedding and carbon going forward along the barrel channel.
CZ, first one I did. Pic before final trimming.
edi
Titanium Putty isn't that hard. It can be sanded easily and if necessary drilled and tapped. It's used to repair threads until the equipment/part can be replaced. I haven't tried to scrape it.
I'm on the other end when it comes to soft bedding. I will often mill out a stock to accept a metal block behind the recoil lug and epoxy it in place. Usually, the block will be installed low enough to allow a skim coat of epoxy. I use this quite a bit to repair stocks on the BSA bolt action rifle stocks that had a tapered, wood dowel pin glued across to strengthen them. The glue used dries out on the small end and the stock ends up cracking in the recoil lug area.
I understand where you're coming from though.
Good luck with that eye by the way.
In my opinion you are defeating the purpose of pillars when adding something between the action and the pillar, you should have hard contact.
As for the thickness I only skim coat unless there is a problem requiring relief.
BB
As for the thickness I only skim coat unless there is a problem requiring relief.
BB
In most cases one tightens the action against pillars. Pillars often do not have exactly the shape of the action and one can decide to have the little void filled with bedding compound or with air. I know which is stronger and transfers heat/vibration better. In our bedding compound the aluminium particles have an av. diameter of 45 micron. Mostly bed against carbon pillars anyway and the competition rifles seem to shoot well like that. Whatever one does one can calculate how much difference it would make either way then make a decision.
edi
Pillars do not have to be metal... they can be poured using bedding compound and they work as well as machined ones... and all pillars do is to prevent stock compression damage as in the case of light weight filled glass stocks.
Stocks are glass bedded to get a perfect fit, I bed on top of the pillars for the same result.
Stocks are glass bedded to get a perfect fit, I bed on top of the pillars for the same result.
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gt, If we apply that logic then why use partial metal pillars at all, a pillar made completely out of any material that is harder than the surrounding material should suffice.
It is an a lot of trouble making, measuring, drilling installing bla bla bla.
I might be out in left field but putting pillars in was never that easy requiring skill and careful measuring and trimming since their length was critical to a successful job so that the screw could not compress the surrounding material either wood or lightweight stock fillers, In fact having metal contact is a lot of work compared to just filling up with bedding compound.
I hold to my opinion that a properly done pillar job requires metal to metal contact and plenty of work, call me old fashioned. just my .02
BB
Very hard to validate one method over the other, but it was always done metal to metal.
If things have evolved to the point that bedding compound can replace metal even aluminium then that is news to me.
Point is if you are going to the trouble of installing pillars then some part of the metal pillar should contact the action
on one end and the opposing metal at the screw head end.
My .02
BB
I would not want my gunsmith to bed my rifle with the metal pillar touching the receiver at all. The idea is a stress free bond between the stock and the receiver. Having a metal pillar touching the receiver concentrates the stress on the pillar rather than across the bedded surface. That's just my preference however
I machine my own aluminium pillars and like to file and fit them to the contour of the action.
Then I use Acraglas and skim above pillars and on my 10/22’s I like to bed the barrel at vies block at least 1-1/2 to prevent droop
Then I use Acraglas and skim above pillars and on my 10/22’s I like to bed the barrel at vies block at least 1-1/2 to prevent droop
Maybe you misunderstood. For example I just bedded a Barnard P action in a stock that was not made for this action. Rear action screw received an alu pillar, this pillar was coated ll round with bedding compound and the screw on to the action with the usual ~ 7nm torque. The pillar sits on the action with the applied pressure, any excess resin is pushed out and the pillar sits metal on metal with the exemption of the odd 45 micron alu particle trapped between or squashed. The advantage is that one has bedding compound where the pillar is not in full contact with the action. As I said a very good way would be to do some calculations about flex etc. I still think the outcome will show it is better to use bedding to fill the gaps.
edi
