MrCrowley wrote:a lot cheaper but a little riskier
Fell off the back of a truck then
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Fell off the back of a truck then
I disowned this barrel modification ever since you shunned carbon fibre with your stingy "student budget" excuses
Here are some more: recession, earth quake, oil spill, mining disaster, rugby world cup...all take money from the taxes I don't pay
In other news, I can start buying smoke cake legally now that Guy Fawkes has arrived. Still need to experiment with piezo buzzers.
Barrel arrived today. The metal plate on the back of the sabot seems to be about 300 micrometers too big and just wont fit. Guess I'll replace that with a washer and sand a few mm of the plastic sabot.
The inside of the barrel almost perfectly accommodates a 1.5" malleable iron barrel nipple, so I've epoxied one of those inside and hopefully it will be enough. I assume all the force will be against the out circumference of the barrel nipple inside the barrel which will push it against what it threads in to (the tee), so I don't think I should be too worried about it unless the gases manage to get in between the barrel and nipple.
Double post, get over it
Would people recommend I weld a malleable iron barrel nipple to the S/S barrel instead of epoxying it? I already have epoxied it but I am a little worried because the galv. nipple is tapered so there is a chance the epoxy at the end of the nipple could crack from stress. I've attached a picture for clarity, green is epoxy, grey the barrel and red the barrel nipple.
The only problem about getting it welded is having the people who do it weld the nipple on straight. It's not like you can weld the nipple on straight going by how straight it is when the barrel is placed on the ground standing up as that usually doesn't relate to how straight it will be once threaded in to a fitting.
Perhaps I'll take the risk and bring the cannon along so they have a reference of how straight it will be when threaded in to a fitting.
Also, does welding the steel bugger any of the heat treatment?
Errrm... WELD IT!! is that really even a question lol?
Your going to need a certain type of filler rod, but luckily your using a higher carbon SS variant so they should bond together nicely.
To make sure its straight - try and get a rod of material that is roughly the same size as the ID of the steel nipple, and then you know the rest - slide it through and into the barrel with spacers to maintain concentric alignment.
I had this issue when i first made my 10XGB hybrid - I welded the barrel to the gun without the stand made. This sucked, and wasn't straight enough to satisfy me so after I made the stand, I got another union, and rewelded everything in the stand - and now its verrrry close to perfectly concentric.
As far as heat treatment go's - no you'll be fine since its austenitic stainless. Just let it cool down naturally - aka air cooling. Since your welding two different metals they will cool at slightly different rates, and you will want to look for cracking near the welds, but even with this you should be fine at the pressure it will see.
I've emailed a local business and hopefully they can do it for under $30, I'll remove the zinc so they don't try charge me anything ridiculous. Might just bring the cannon with me so they can line it up that way as I don't have any pipe that fits inside the nipple. Anyway, they seem like the type of people who would enjoy someone bringing in something like this.
Those are always the best people to get help from!
I'm currently working on trying to bring an aftermarket product to the freestyle stand up jetski world and I'm lucky to have a buddy who's not only excellent at welding aluminum, but also interested in the product hes going to help us weld.
Well I've done something right, can't get the epoxied nipple out of the barrel
I used a heat gun on the joint for about 10min, scraping away the exterior epoxy while using some form of a nail punch where the nipple meets the pipe wall to try bang the barrel loose. Mind you, that's all without using a plumbing wrench, I'm sure my big plumbing wrench is more than capable of dismantling it but seeing as I don't want vice or wrench marks on my lovely S/S tube, it's going to have to stay for now.
I assume the heat gun has buggered the strength of the epoxy permanently so the fitting definitely has to come off?
Ha, I know the feeling. the good thing about SS is that it can always be buffed up! I may shine 10XGB to a mirror finish one day... probably not, but it would look cool!
Just make sure you get your wrench to grip on the first try, drag marks are hard to get rid of.
Freeze the end of the barrel with the coldest stuff you have available (be it dry ice, one of those computer duster spray cans, or just salted icewater), then hit it full blast with a propane torch for a few seconds. Hopefully the thermal shock will break the bond.
What kind of epoxy did you use?
So your barrel is not seamless? Congrats on getting a metal barrel though. So much better. They should be able to tell you what spec it is. For instance "AS 1074" or something like that.
No, not seamless. I guess through some manufacturing process they ground down the seam. Good pointer about the spec, didn't ask about that.
I have one of those computer dusters for my microscope, hopefully this wont use a lot of it up as I just bought it and they're about $30 over here (residue free, though)
If you have the option of welding, go for it.
Was firing it last night because it was Guy Fawkes and all, the barrel warms up really fast, it's like you can feel the flame front past down the barrel; which is slightly unnerving but I'll get used to it. Got some sparks out the barrel too
I wasn't firing any projectiles, at the detest of my neighbours, which I hope is the reason the piston was bouncing almost completely closed again. I definitely noticed a reduction in performance judging from the sound of it. Either that or my bumper needs fixing.
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