Armor removal and armor screws

[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.

[motto (RIP)]

Lots of ideas to choose from here Gina. You can mix and match from dead blow hammers to blue tongue spanners, from shouting a curse to emptying your purse.
No golfer plays with only one club, they have a bag of them.

David

[Mrs Vampire]

The "No golfer plays with a single club" rule is spot on.

3/4 drive drag links hard to get so have one on back order from the states. ( snap on as advised by Steve)

In the meantime ground down a hex drive and now have thirteen of the 5/8 screws undone and only one of the 3/8.

A T bar with a couple of lengths of water pipe to give extra leverage has done the best so far.

The rattle gun is impossible to keep in for more than a few hits and it damages the slot dreadfully. I will take my Big Hitter rivet gun with a slot snap and give them all a good rattle.

I will also hit them with some heat. Heating is a bit of a hazard given the amount of oil , grease etc built up in the engine compartment and the risk of fire.

So far bit over half of the big screws on the rear armor. First time out since 1942 so far as I can tell.

Below reground home made drag link ( about five grinds for ten screws) I use grinding paste in the slot to assist with keeping the blade engaged. The screw has been polished to colour parade colour standard :/