doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Metric screws taps and dies

The absolute best I have ever used is Cabots TASGON which was banned by the EPA around 1980 because it contained some creosote. I have about a pint which has to last the rest of my life so I only use it as a last resort. I have been searching for a suitable replacement ever since and currently have at least 18 brands of penetrating oils in my shop. I'd like to find the time to devise a test to check breaking torque with equally corroded fasteners using everything on my shelf.

I've recently tried Burlite and pure Oil of Wintergreen on gun screws and have found them good, but I think it's still too early to say I've found the Holy Grail. I want to try Mouse Milk because I've heard great things about it. But I heard great things about Kroil and PB Blaster and was not impressed. I like Zep 45, StrongArm, and 50/50 ATF-acetone. But it's tough to say that something might have worked better or worse when you have a success or failure. If I use more than one brand on the same screw before it breaks loose, how can I say for sure which one finally broke the bond of corrosion? Or perhaps the combination of two or more may have done what no single brand would have accomplished.

I still say that patience is the best tool you have when dealing with a stuck screw. I have had many that resisted all reasonable efforts for weeks or even months, and then finally broke loose and came out intact and undamaged. It would have been so easy to grab a larger handled screwdriver, and wring off the head or burr the slot, and then go through hell, drilling, tapping, and finding or making new screws. I still encounter some that won't cooperate, but damn few. I currently have a compensating ballscrew on a slightly rusty Lefever I grade that has had everything in my arsenal thrown at it, off and on for over a year. It almost seems as if there may be some type of thread-locker in the threads that has resisted moderate heating and won't let the penetrating oils get into the threads. It's looking like I may have to weld a nut on the slot end to remove it, and then cut off the nut and re-dress the end.

That aforementioned TASGON worked many times on things that I would've bet large money that I'd have to burn or drill out. If you ever see some at a flea market or garage sale... buy it! I do say with confidence that Kroil is over-rated hype. We used Kroil exclusively when I worked for General Motors. Most of our equipment was indoors and not in wet or corrosive environments. Even with all that, I saw many many times where Kroil failed to penetrate more than a couple threads deep, even after prolonged repeated soaks. I used Kroil enough times over enough years to be emphatic about this. I personally don't think it's much better than straight kerosene.

Thanks for the suppliers, checked them all out and of all places find one at Enco so I ordered three. Just hope they have them in stock. I can now make a die and problem solved for now. I will most likely tig four of the screw slots and recut them but the sear pins I will have to make as they were rusted in too badly and had to drill them out. At least it keeps me off the streets.

Finally got the next step in the restoration of my Simpson. got the screws all made now add the decoration to the heads and start the polishing. The screws were so badly rusted in that I ended up drilling them out, rather than damaging the action, its kinda strange because the screw looked like someone used a locking compounds that rusted the threads only the rest of the screw was clean.
The screw threads are M4.8 through out the action. No dies seem to be available but I did get a tap and ended up making dies from W-1 drill rod the screws are made from 1144 stressproof it machines really nice. The big problem I found is the timing of the heads that took longer to get that correct. I have built many rifles but never encountered a problem like this before. Shotguns are a different thing altogether for me. So anyway thought I would put this up for what its worth.

rgh,
Nice work. It's hard to tell what skills a member has when they ask a question. No doubt, you've walked around a lathe or two before.

For taps, I've made and number of them by singlepointing them. The problem is with metric taps you need a metric lathe. Not something everyone has.

Good luck with that project. Post some pix when done.

rgh25
To time the heads quickly,make the head thicker than necessary,put a temporary slot in it,turn the screw up tight and then mark the location of the permanent slot.
Mike