knight guitars
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Suitable bungs
Hi all been plugging steel barrels with hand made wooden dowels prior to soaking them in our bluing solution. Which is long winded and Im sure theres
better ways for it to be done.
What bungs are available in a suitable material to survive immersion in the following forumar at a constant temp of 140c
NaOh
NaNo3
NaNo2
Na3Po4
If the bungs were resistant to common solvents such as cellulose thinners or acetone that would be beneficial as we use these in degreasing, this
caracteristic is not essential as Im sure we can find a way different degreasing solvents but it would be handy if we didnt need to.
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m1tanker78
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Can't think of the name ATM but what about those rubber plugs that have a screw and wing nut to mash the rubber down and expand it. You could probably
buy an assortment of different sizes or even make your own. I want to say I've seen them at Lowe's but don't quote me on that.
I can't guarantee that the rubber will survive indefinitely, given the conditions, but it may be worth a try. The rubber may even give you a [better]
seal if you work with rifled bores...
Tank
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Mr. Wizard
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Why not get some plastic sheeting of polyethylene, mylar, or some other resistant material and cover the wooden plug with this material. Leave a space
in front of the plug, so the entrance of the plug forces the plastic against the rim of the barrel without stretching or tearing it. Trim the plastic
with a razor to allow the bluing solution to the muzzle of the barrel. Teflon plumbing tape might work.
Custom turned cones of polyethylene or teflon could be pulled tight with a threaded rod through the barrel and some wing-nuts. Protect the barrel from
the threads with some shrink tubing. Anybody with a lathe and some rod stock should be able to turn these simple plugs. Lead castings might even work
if they hold up to the blueing solution. Lead will form a seal against metal under pressure.
The cartridge end of the barrel might be sealed with an empty cartridge filled with solder and a threaded rod extending to the muzzle. The cartridge
casing , firmly soldered to the rod, would be sealed with a few wraps of teflon tape at the rim, and the rod pulled tight with a wing-nut to seal it.
Extruded teflon indicating a seal at the chamber end.
Knowing grease and oil are problems with barrel preparation, these methods should avoid problems.
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knight guitars
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Only problems I can see with using threaded rods all the way through the barrel is that your muzzel end seal would cover up the muzzel crown and it
would not get treated with the bluing solution.
Also the size of the common bores I work on are quite small .177 cal 4.5mm .20 cal 5mm .22 cal 5.5mm and .25cal 6.5mm (well 6.35mm to be exact) and
that means you would be using a very small rod which means having it turned by someone which all means unneeded expense.
But you idea would work a treat for shotgun barrels. I dont mind if the bungs only last a job or two as long as there affordable. Ill have a go with
some rubber bungs and let you know how we get on.
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Mr. Wizard
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Quote: Originally posted by knight guitars  | Only problems I can see with using threaded rods all the way through the barrel is that your muzzel end seal would cover up the muzzel crown and it
would not get treated with the bluing solution.
Also the size of the common bores I work on are quite small .177 cal 4.5mm .20 cal 5mm .22 cal 5.5mm and .25cal 6.5mm (well 6.35mm to be exact) and
that means you would be using a very small rod which means having it turned by someone which all means unneeded expense.
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I understand about blueing the muzzle crown, that's why I mentioned using a cone shaped plug, which would allow access by the solution. As for the
narrow bore, you might have to find some suitable brass brazing, or steel gas welding rod, and thread the ends. Rods too short can be quickly gas
welded together and lightly hammered back to a narrow diameter.
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cyanureeves
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what about using red RTV on the ends about an inch or so deep ?
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knight guitars
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First I'd like to say thanks for your idea's, Wizard re reading your post I can see what your on about and if I was working on a standard barrel
design I would make up threaded jigs, but every barrel length I work with atm is different and so that makes it impracticable at the moment and
slightly over the top but I will certainly be doing so for larger caliber work. I hadent even heard of RTV but I'll keep that in mind, I would have
to try it out to see how it does for durability though it looks a bit expensive for repeated use it may be good for a one off job when I dont have an
appropriate bung to hand.
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Rogeryermaw
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RTV gasket compound actually sounds like a pretty good idea. it is meant to survive quite harsh conditions. heat, oil, fuel, coolant, and the
corrosive gasses of combustion. it can be gotten in tubes like caulking and is relatively inexpensive. might be worth a try on a piece of scrap to
test suitability for your application. a small tube of it when i have an automotive project is usually less than 5 or 6 dollars. good luck finding the
right solution!
i need to check on this, but if i remember right, strong acid (sulfuric i believe) was one of the few things that dissolve it and that still takes a
good while. also acetone is mildly effective at dissolving RTV and some ketone copolymer solvents.
[Edited on 19-5-2011 by Rogeryermaw]
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Mr. Wizard
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One thing that will quickly ruin well hardened RTV (Room Temperature Vulcanizing) Silicone is gasoline. It causes it to swell and fragment. It doesn't
seem to dissolve, it just turns to a crumbly gel, which doesn't adhere well. I learned this while patching a carburetor gasket on a small engine. It
has been useful in removing RTV silicone from surfaces. I'm not sure which component in the gasoline causes this. Gasoline here in the US is a blend
of many things and often contains 10% ethanol.
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Rogeryermaw
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| Quote: Originally posted by Mr. Wizard | | One thing that will quickly ruin well hardened RTV (Room Temperature Vulcanizing) Silicone is gasoline. It causes it to swell and fragment. It doesn't
seem to dissolve, it just turns to a crumbly gel, which doesn't adhere well. I learned this while patching a carburetor gasket on a small engine. It
has been useful in removing RTV silicone from surfaces. I'm not sure which component in the gasoline causes this. Gasoline here in the US is a blend
of many things and often contains 10% ethanol. |
it would likely be acetone or a similar chemical. it also depends on the grade of RTV as some of them are formulated specifically to handle fuel
exposure. the black ultra is for general use, the red is for high temp applications like around the intake manifold where hot coolant passes through.
the blue is for sensitive equipment and the ultra gray for rigidity in high torque apps. there are many different types and they have some differing
properties. here is a link to the permatex website: http://www.permatex.com/products/automotive/automotive_gaske...
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