I use a lot of different epoxies at work. Some are glass filled and hard as hell (brittle). Some are not filled at all, and not very strong.
I forget the part number, but there is a product made by Hysol (might be owned by 3M now) that would be a good choice. I will get the part number for you Monday when I am at work.
It is very similar in composition to JB Weld, which I use alot of at home. JB weld will be easier to get than the HYSOL product, so I would tend to recommend it over anything else. I believe JB Weld is metal filled. It is very strong and also takes temperature well.
I am not sure about how much room you should leave for the epoxy. It depends on the viscosity of the stuff at the time you install the liner, and that is largely going to be temperature dependant.
A somewhat guess for clearance would be 5-8 mils around (10-15 mils total diameter to diameter).
I would warm both the barrel and the liner to about 100 - 105 F. Mix the epoxy once the metal is warm and smear it everywhere, putting more in the barrel than on the liner. Heating the barrel will thin the epoxy and allow things to flow more nicely, allowing a closer liner to barrel fit as well. You don't want to heat the epoxy prior to applying it as the cure process accelerates as soon as it is heated and you want as much working time as possible. Heating the barrel will heat the epoxy.
Force the liner in and the excess epoxy will be forced out. You will probably need a hydralic ram or press to push the liner in. I would be looking at my hydralic wood splitter about this time
ONce you press it in, leave it in the press for 24 hours to let the epoxy cure.
Your battle will be with the trapped air however. You could possibly put a small hole in the breech of the unlined barel to allow the trapped air to exit. If you don't give the air a planned way out, it will push the epoxy out as you push the liner in.
O ya, a rough surface on both the liner OD and barrel ID is prefered for better adhesion. Course grit sandblasting or rough (40-60 grit) sandpaper would do the job. Cleanliness is important as well. No dust, no oil on the surfaces to be glued.
As far as "CONAP", that is the name of the manufacturer rather than the name of a specific epoxy. They make lots of different epoxies, so you need to specify more than "CONAP". If you use any of their products, stay away from Urethanes. Some are more flaky than others, but Urethanes in general have this annoying habit of sometimes not setting up for various reasons. Some need moisture or they won't set up, while others won't set up if they are exposed to the slightest hint of moisture. Urethanes in general are not for the timid to play with.
Rick
