J E Custom
Well-Known Member
There have been many post on bedding, and the different kinds that you should use.
I always recommend something that Is designed for this use and the reasons are many but many have there favorite compound and don't intend to change. So I thought I would pass this little trick
on that may help with your choice.
There has also been lots of decisions about how soon you can take your action out of the bedding and when you can torque the action and shoot it.
With all of the different compounds used, there is no good answer because of the different cure rates, heat while curing, shrinkage and strength. wanting to know more and be able to discuss with intelligence I decided to do some testing that would help clear this up.
I recently pillar bedded a barreled action with my favorite compound and had plenty of time to test.
After installing the pillars and prepping the stock and barreled action I mixed my bedding compound
at 70o and started the clock.
The compound gives cure time and use time, so I wanted my test to verify these times. I always
mix up more than I need to keep from being short and having holidays in the finished bedding.
After setting the action and clamping it in place the surplus bedding compound is squeezed out.
After removing the excess and collecting it, I made a bunch of small beads about 3/16'' x 6'' in a piece of angle with release agent on it. and began the test. In 70o still air, I started monitoring
the temperature change in the compound. (In the past some bedding materials heated up a noticeable amount).
After 2 hours, the first sample was still very flexible and tacky so I left it alone. 4 hours in, it had become cured to the touch but was still not very hard so I left this sample in tack and moved on.
8 Hours later, the sample was cold to the touch and exothermic reaction appeared to be constant.
so I tried to bend one of my samples to the breaking point. Much to my surprise, it bent almost 90o
before it broke. (It was no where near its full strength)
Waiting the full cure time in the instructions, I tested another sample by bending it and again it bent close to 45o before it broke. it could be filed but very easily.
I always recommended several days before removal of the action from the stock and discovered that the time listed was minimal and the compound was not up to full strength. also after 5 to 7 days (Or more) I felt I could torque and shoot the rifle. I was wrong again. every day I would brake another sample and found out that the compound samples flexed before breaking up to 10 days.
I feel that if the compound will still flex before breaking it is not to full strength and still compressible. making it risky to torque the action before full hardness is reached.
I then decided to test some other compounds by making some samples and had different results
and these are my observations.
The faster the compound cured the higher the heat and shrinkage. (The poorer the final fit)
The slower the cure time the lower the heat and the shrinkage. (Not exactly rocket science) .
Different compounds showed different results and some "Never" totally set up hard and would bend
before breaking.
This test was very simple and a good way to evaluate your preferred compound to know when to remove the action without damage to the bedding, when to torque the action and when you can shoot the rifle without damaging the bedding. In all cases the manufactures times were insufficient
and more time was necessary in my opinion for the use and longevity we need.
I hope this helps someone and keeps them from destroying a perfectly good bedding job by torqueing and shooting it to soon.
J E CUSTOM
I always recommend something that Is designed for this use and the reasons are many but many have there favorite compound and don't intend to change. So I thought I would pass this little trick
on that may help with your choice.
There has also been lots of decisions about how soon you can take your action out of the bedding and when you can torque the action and shoot it.
With all of the different compounds used, there is no good answer because of the different cure rates, heat while curing, shrinkage and strength. wanting to know more and be able to discuss with intelligence I decided to do some testing that would help clear this up.
I recently pillar bedded a barreled action with my favorite compound and had plenty of time to test.
After installing the pillars and prepping the stock and barreled action I mixed my bedding compound
at 70o and started the clock.
The compound gives cure time and use time, so I wanted my test to verify these times. I always
mix up more than I need to keep from being short and having holidays in the finished bedding.
After setting the action and clamping it in place the surplus bedding compound is squeezed out.
After removing the excess and collecting it, I made a bunch of small beads about 3/16'' x 6'' in a piece of angle with release agent on it. and began the test. In 70o still air, I started monitoring
the temperature change in the compound. (In the past some bedding materials heated up a noticeable amount).
After 2 hours, the first sample was still very flexible and tacky so I left it alone. 4 hours in, it had become cured to the touch but was still not very hard so I left this sample in tack and moved on.
8 Hours later, the sample was cold to the touch and exothermic reaction appeared to be constant.
so I tried to bend one of my samples to the breaking point. Much to my surprise, it bent almost 90o
before it broke. (It was no where near its full strength)
Waiting the full cure time in the instructions, I tested another sample by bending it and again it bent close to 45o before it broke. it could be filed but very easily.
I always recommended several days before removal of the action from the stock and discovered that the time listed was minimal and the compound was not up to full strength. also after 5 to 7 days (Or more) I felt I could torque and shoot the rifle. I was wrong again. every day I would brake another sample and found out that the compound samples flexed before breaking up to 10 days.
I feel that if the compound will still flex before breaking it is not to full strength and still compressible. making it risky to torque the action before full hardness is reached.
I then decided to test some other compounds by making some samples and had different results
and these are my observations.
The faster the compound cured the higher the heat and shrinkage. (The poorer the final fit)
The slower the cure time the lower the heat and the shrinkage. (Not exactly rocket science) .
Different compounds showed different results and some "Never" totally set up hard and would bend
before breaking.
This test was very simple and a good way to evaluate your preferred compound to know when to remove the action without damage to the bedding, when to torque the action and when you can shoot the rifle without damaging the bedding. In all cases the manufactures times were insufficient
and more time was necessary in my opinion for the use and longevity we need.
I hope this helps someone and keeps them from destroying a perfectly good bedding job by torqueing and shooting it to soon.
J E CUSTOM
