Armor removal and armor screws

[Lauren Child]

Originally Posted by Gina Vampire

Now that looks very noice but very very hard to find one :?/

Unfortunately yes, but it gives you an idea of what to look for (or to try and replicate with modern tools). Basically you need a shock push and twist motion at the same time, with a bit that fits exactly into the slot (very little play).

[Mrs Vampire]

The results of my latest attempts at unscrewing the bolts.

I have managed to get all but ten of the large bolts out and have made good progress on the smaller ones.

I have made some , for me, startling discoveries. The penetrants I have use made virtually no penetration apart form some very slight surface intrusion.

All my theories about penetrants are out the window. My primary penetrant was WD-40 with Methyl Salicylate added to it. I have used methyl Salicylate straight, RP-7 , CRC, Reducteur H-72 and Wurst Rost Off plus. Not one of these made any penetration worth speaking of. Once I had the screws out a sixteenth they aided in further extraction but they played no part at all in helping with initial release.

I will experiment with phosphoric acid and see if that gets in. The next attempt will be to heat and cool using penetrant along the way .

The best helper yet has been a small rivet gun with a chisel end , my 1/2 inch drive rattle gun and the long handled T bar with my home made drag link.

The small rivet gun is not a big hitter but has a very high cycle. I tried my big hitter Rivet gun with a lower cycle rate without success. Likewise my 3/4 rattle gun is to hard to hold in place and hits to hard to control.

Photos are of extracted screws showing how nearly new some are , how little rust and how crummy the penetration...they are all dry.
Also a heap of removed bolts...just because I am so pleased to have them out... the very expensive penetrant that is useless the el-cheepo rivet gun that did the best work and the head of a screw showing the slight damage done in removing them.

Not one of these screws would move using a drag link with a four foot extension bar ( it broke the drag link) or using either rattle gun the little rivet gun moved them in seconds.

I checked the parts book and finally found the tool originally designated for Armour removal...it was a 1/2 inch drive drag link socket

[Steve Greenberg]

Gina,
Have you tried Kroil? I have used it before and it does seem to penetrate after it sits for a bit. http://www.kanolabs.com/
Steve

[maple_leaf_eh]

How about diesel fuel in a squirt bottle? I had to clean some minor rust and grease spots off a rifle barrel. Diesel and a scrub brush worked as good as any more expensive fluid.

BTW, I was told that Kroil is only sold business to business, and not to consumers.

[Mrs Vampire]

Terry Diesel is harder to get in than WD...I have had these bolts soaking for a couple of months now so its tough to get something down into an inch and a half of armour.

Steve I don't seem to be able to get that in Oz and they wont ship...except at exorbitant prices. I will try to hunt some out the reviews seem positive.

I got onto another couple of penetrants one is a Loctite product another a local Queensland mixture Inox. The Loctite is a freeze it idea Inox products seems to have MEK amongst other things in it.

I hit them with heat today and got one more big one out and a few more of the little 'uns .

The golf bag looks a bit like this now.

[Lynn Eades]

Gina, It is probably obvious to you, but may not be to some, so I will state the obvious;
The countersunk screw is (was) designed to be tightened (loosened) from the nut end. The taper is (was) supposed to sit cleanly in the countersink, and "bite into the taper. The purpose of the slot in the head is (was) to hold the screw from turning while it was still loose. I guess it can be likened to a taper on a shaft, when the two components are assembled nice and clean, they will come apart cleanly (easier than when rusted etc)
I would expect those heads to seal completely metal to metal and rust free between the faces. To me the best shot is to back the nuts off while the screws are still "stuck", and then pop them out.
I hope that helps somebody. It has worked for me, at least some times. (Carrier screws are a lot smaller)
Your various penetrants or rust removing compounds will have a better chance working in the threads of tensioned c/s screw.

[Mrs Vampire]

Lynn

All of the screws that hold the Armor on the Stuart and Grant are captive. ( the nuts are welded in place) 'twould be but a simple task were it otherwise. Likewise that theory would not work on aeroplanes where nearly every screw is into an anchor nut countersunk or otherwise. The P-40 gave me many interesting hours drilling the rusted ones out and replacing anchor nuts. ( though many were reid and prince type screws there were a good many slot types..)

I'll check out the half track but I think the same applies there.