thermal fit upper assembly question.
- Thread starter din
- Start date
Heat gun or low flame torch on the receiver snout. Stick barrel in. Done.
I use a 1200 W heat gun on high for about 60-90 seconds then slide it in dry.
I mount the upper in one of these while Im heating the threads:
Wheeler Upper Vice Block (# 156888) ($32)
To remove the barrel I mount it the same, heat the threads for about 90 secs with heat gun on high and then whack the barrel out with
- 1”x12” Wooden Dial Rod ($10)
- 16oz Rubber Mallet ($12)
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Dry makes sense to me for sure... the goal is to have the barrel and extension act like a single piece of metal, why add something between them?
If you warm the throat enough there's enough room (unless the barrel extension somehow is super-oversized) to do it dry.
A "security blanket" thin coat of any petro based lube will probably cook off once the rifle is put to use, if it isn't squished/forced out during the slip fit. But the metal/metal join around the clockface is what you want, and the lube really isn't helping that. So it isn't a great "security blanket."
A "security blanket" thin coat of any petro based lube will probably cook off once the rifle is put to use, if it isn't squished/forced out during the slip fit. But the metal/metal join around the clockface is what you want, and the lube really isn't helping that. So it isn't a great "security blanket."
I do use a grease. I use a very thin coating of CMC Silaramac brake caliper grease, which won't burn off, and slide the barrel in.
I use SS shim stock (.001 or .0015 depending on the tolerances), and thermal fit every upper/barrel I have. So many of the uppers I prefer aren't undersized, so shim stock takes care of that.
In my case, I use an Odin Works vice block and a heat gun. I prefer to have at least .0015" extra room in the upper before I slide the shimmed barrel in. The barrel extension is one helluva heat sink and you don't have much time.
As far as removing a thermal fit barrel, that thin coat of Silaramic grease, the vice block in my vice, and an old broom handle I cut off provides all of the muscle needed without any heat. I hold onto the barrel, use a dead blow hammer, and don't go full caveman....
I use SS shim stock (.001 or .0015 depending on the tolerances), and thermal fit every upper/barrel I have. So many of the uppers I prefer aren't undersized, so shim stock takes care of that.
In my case, I use an Odin Works vice block and a heat gun. I prefer to have at least .0015" extra room in the upper before I slide the shimmed barrel in. The barrel extension is one helluva heat sink and you don't have much time.
As far as removing a thermal fit barrel, that thin coat of Silaramic grease, the vice block in my vice, and an old broom handle I cut off provides all of the muscle needed without any heat. I hold onto the barrel, use a dead blow hammer, and don't go full caveman....
Aeroshell 64 on the barrel extension and threads. Heat with a torch or heat gun. I use a torch and typically only need to hit the upper with it for a few seconds.
If you want to mate the extension to the upper as closely as possible, while still being able to disassemble it in the future, use loctite 620 on the extension and aeroshell on the threads.
If you want to mate the extension to the upper as closely as possible, while still being able to disassemble it in the future, use loctite 620 on the extension and aeroshell on the threads.
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