Armor removal and armor screws

[Mrs Vampire]

Hi Steve.

I have used those drag link sockets and they break of at around the second hit with my impact wrench. maybe I should be using snap on
I guess I could use them when the bolts are loose enough ...

My current driver is a ground down Allen head impact drive socket.

I get ones that are big enough to provide a good screw driver head when ground. I am careful not to over heat in the grinding process and the length gives me lots of room for extra grinds when the driver gets rounded or bent.

The problem with blade drives and impact wrenches is keeping the driver in the slot, it jumps out as soon as it gets going on account of the physics of it all.

All that said ...the inch drive rattle gun makes not the slightest difference to most of the bolts.

I will make up a leaf spring driver as suggested as well as the modified pipe wrench thingy ....being able to put a substantially long bar through it makes it far more powerful than a T bar but i suspect as advised earlier I will need a couple of friends to help with it.

I think getting things low and close to the job is also important so the leaf spring idea has the advantage of me being able to make the thing right down close to the job.....all the sockets etc mean the leverage is a couple of inches of the armor so keeping the thing vertical while straining against the bolt becomes an issue.

Terry ...if there are other forums that tackle removing armor bolts I have been unable to find them...in fact when it comes to practical help MLU is the best around as far as I have found ...that said if anyone knows of another source i would be most grateful for links.

many many thanks for all of your combined wisdomes

[motto (RIP)]

I understand the issues now with the nuts being captive or inaccessible you only have the head of the screw to work on.
The most effective tool I encountered for undoing screws on aircraft (sometimes by the hundred) was a rivet gun with tip adaptor and handle. The principle was that the shock load was applied completely independent of any radial force unlike an impact driver. Of course the screws in that case were 3/16" or 1/4" diameter.
To translate the principle to what you are attempting would require a jack-hammer or pavement breaker fitted with an appropriate tip and a handle to apply rotational force to it.
Maybe just fantasy but who knows what people have laying about the place.

David

[chris vickery]

There is also a tool which is hand impact driver of sorts, typically used on things like auto door hinge screws etc.
Look up Lisle 29200 on the internet to see what I'm talking about. Other companies such as Proto, SnapOn etc make them as well.
If you opt to purchase one, buy a good one.
It works like this;
You have a handle which has a striking surface at one end and a hex driver on the other. There are some mechanics inside which allows it to be used for driving in or loosening out screws by twisting the shaft one way or the other to change drive direction.
They usually come in a kit with various types of bits including the parallel ground type slotted bits.
You place the appropriate bit in the driver, place it into the screw and strike the end of the handle with a large hammer. I am sure if the bolt were heated it would help. I have used it in the past and it worked great.
I have often found as well that it benefits to try tightening rusted bolts a bit before trying to loosen them.

[Richard Farrant]

Originally Posted by motto

I understand the issues now with the nuts being captive or inaccessible you only have the head of the screw to work on.
The most effective tool I encountered for undoing screws on aircraft (sometimes by the hundred) was a rivet gun with tip adaptor and handle. The principle was that the shock load was applied completely independent of any radial force unlike an impact driver. Of course the screws in that case were 3/16" or 1/4" diameter.
To translate the principle to what you are attempting would require a jack-hammer or pavement breaker fitted with an appropriate tip and a handle to apply rotational force to it.
Maybe just fantasy but who knows what people have laying about the place.

David

David,
You have given me an idea here, an air needle gun or descaling tool. Remove the needles and make an adaptor to fit on of the screwdriver ends in to.

I have gone through the pain of these countersink screws on wartime British armour although they have deeper heads the slot is shallow and narrow. The head being more pronounced allows a flat drift to be used to knock the head sideways a fraction to break rust seal and allow penetrating fluid in.

[Peter Walsh]

I understand the issues now with the nuts being captive or inaccessible you only have the head of the screw to work on.
The most effective tool I encountered for undoing screws on aircraft (sometimes by the hundred) was a rivet gun with tip adaptor and handle. The principle was that the shock load was applied completely independent of any radial force unlike an impact driver. Of course the screws in that case were 3/16" or 1/4" diameter.
To translate the principle to what you are attempting would require a jack-hammer or pavement breaker fitted with an appropriate tip and a handle to apply rotational force to it.
Maybe just fantasy but who knows what people have laying about the place.

David

In the workshop where I work we use a snap-on el brutus screw removal tool which is similar to this tool:

http://www.aetools.co.uk/product-ape...ractor-300.php

It is a smaller version a locally made tool referred to as a "gutbuster" that we used in the RAAF on the F111 aircraft for removing stubborn panel screws. It works on leverage to hold the screwdriver tip down while you turn it with a rachet or speedbrace. It has an anchor point at one end and a handle at the other end. In the middle is a 3/8" male/female square drive for the tip holder and rachet that can slide along the lever to reach the screwhead you are trying to undo. The closer the tip is to the anchor point, the more leverage you have. The lever and handle were up to 3 feet long. We broke a lot of tips and some even ended up with a nice twist like decorative wrought iron.

You have to remove a screw or bolt (not necessarily the same size/type as you are trying to remove) close to the screw you want to remove and use that screw or bolt to secure the anchor point of the gutbuster to the assembly you are working on. The anchor point had a round metal plate with holes of different sizes to take screws/bolts of various sizes. The gutbuster was a two person job where el brutus can be used by one person easily. In the workshop, we used to chew out up to half of the screws trying to remove them before we started using el brutus. If any, we only chew out the first screw for the first anchor point now. Absolute magic.

As a last resort you could probably make a version of the gutbuster and use heat and penetrant.

[colin jones]

Hi Gina, my wife said that she uses the gut buster on the F18s and said there is nothing like them. I don't think it would be hard to make a tool of similar design. I will be making one when I start mine.
Colin.

[Mrs Vampire]

Interesting gadget...but very expensive .

https://www.youtube.com/watch?v=yktPX2jVSTk

[universalgrl]

As I was a master aircraft technician I learned the correct way to extract frozen screws.
I saved ALL the screws on my carriers front plate including the 4 1/4 inch screws for the log book holder.
Use a penetrant of your choice (over several days) I use wd-40. Use a dremel with a fibre wheel to clean out the screw slot and remove burrs, make sure the sides of the slot are parallel to each other.
Make sure your tool bits are sharp and don't show any signs of twisting, the bits can cam out otherwise wrecking the screw slot.
Impact hammer with the extractor and appropriate bit or hand held impact and a zero bounce hammer.
If all else fails MIG a tack weld on the screw and attack the fastener on the other side, nuts are cheap.