GTA
All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Engineering- Research & Development => Topic started by: PakProtector on September 28, 2013, 09:25:21 PM
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Have any of y'all tried diamond paste for bore lapping? It is abrasive as all get out, ought to have reasonable consistency of cutting particle size, and comes in various grits like this stuff:
http://www.ebay.com/itm/170967969156?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649 (http://www.ebay.com/itm/170967969156?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649)
The stuff in that auction is 3.5 micron, but the seller lists many other grits. Looks like a fine but expensive stuff to try with a cast lead plug...:) Well, several plugs; can't go embedding the coarse stuff and then switch to 'fine'...
cheers,
Douglas
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I've only tried JB Bore Paste and Tubbs Final Finish.
I hand lap with JB and those round hard felt pellets (like cleaning pellets) Brownells sells with great results.
I coat cleaning pellets with JB and just shoot a bunch in succession down my airgun barrels (non choked).
Tubbs Final Finish had 5 grits that started off as 'coarse' and went to 'super fine'. It was embedded on the bullet and you handloaded them then fired cleaning in between every shot for the first 20 shots then at the end of each 10 shot string.
It was a pain but my barrel was MUCH easier to clean after.
The part that caught my eye was 'embed'. I'm not sure that's such a good thing. If you could remove all traces of the paste after with cleaning solvents after I imagine it would work great.
A cleaning pellet fired down an airgun bore smooths things out pretty good.
The lead slug coated with an abrasive should actually remove imperfections in the bore and make it uniform.
Tubbs Final Finish claimed to remove no more than .0001" from the bore.
The boys on the Marlin website suggested using a clover oil recipe and soft cast bullets at 'ppffft' velocities - I went with Tubbs.
I don't see why it wouldn't work - my concern would be getting it all out after.
You could go in stages checking with a bore scope to check on progress.
I know one thing - bore lapping works!
:)
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Douglas
I have used Dia-paste http://www.dmtsharp.com/sharpeners/specialty/dia-paste-1/ (http://www.dmtsharp.com/sharpeners/specialty/dia-paste-1/)
in cases of extreme need.
I've encountered Spanish made black powder barrels that tooling marks that were so pronounced you could rattle a pick up and down them.
This is what I mean by extreme need. I think embedding is an issue but in cases like this where there is going to be several following processes I'll use it.
If you want to go old school and stay with tradition then dry emery powder is the stuff of choice. The rock polishing folks are a good source for small quantities. The lap is oiled and rolled in emery powder. Whatever process I use I always finish with JB Bore and then polish with a patch or felt with JB Bright.
HTH
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Here is a pic of one of those "extreme need" cases
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WOW! IS that a Barrel or a rifled Cheese grater? :o
Bill
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WOW! IS that a Barrel or a rifled Cheese grater? :o
Bill
It is actually a tunnel through the Alps drilled by that huge boring machine just ahead of applying the shot-crete to the walls...:)
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WOW! IS that a Barrel or a rifled Cheese grater? :o
Bill
It is actually a tunnel through the Alps drilled by that huge boring machine just ahead of applying the shot-crete to the walls...:)
Haha yup either of those work for me