Question About WW II Pilot Jack Knife

[giovanni8]

Hello folks, this is my first post to the AAPK, hope there's someone who can offer a bit of advice- I just bought a WW II Army Air Corp Pilots Jack Knife on e-bay and it looks like it will need some cleaning and maybe some retooling. I have not actually received it yet, and will post some pix when I do. It looks like it's been made by United, Grand Rapids Mich. The seller said he could not open the saw blade and did not want to force it.
Need info from anyone who's done restoration on a jack knife- such as:
1) What's the best way to clean the plastic bolsters?
2) What's a good penetrant to loosen the frozen blade?
3) What is best method to polish the tarnish off the main blade?
4) Can the saw blade be replaced if it's too far gone? Can the teeth be resharpened?

Basically I need to set up some dialog with an SME on this unit- I paid around $20 for it, mostly because the seller did not know what he had- he just called it an old jack knife found in a barn. After I took a better look at it, I realized it was military and linked it back to the proper description.
Anyway, I have about 40 knives in the collection at the moment, this one will make a fantastic addition, but it's going to need restoration, which is why we're here.
Appreciate any useful information, eps. from someone who has taken one of these units apart.
Regards, Giovanni

[Iron Hoarder]

We need pictures. And welcome to the site.

[jerryd6818]

Welcome aboard. Always glad to see new members.

You'll get lots of opinions here with lots of solutions born from experience. There's just a ton of knowledge stored up in the brains of these knife addicts.

These are my opinions.

2) What's a good penetrate to loosen the frozen blade?

Some guys prefer a mineral oil soak for several days to a week. I prefer penetrating oil such as Liquid Wrench or my personal favorite, PB Blaster. There are several brands. Take a look. You may already have a favorite. Be patient. Let it set for a couple of days and work.
http://www.amazon.com/s?ie=UTF8&keyword ... ack&page=1

1) What's the best way to clean the plastic bolsters?
3) What is best method to polish the tarnish off the main blade?

For me, the same answer to both questions. Mothers Mag & Aluminum Polish. About $6 or $7 at your local automotive supply store.

4) Can the saw blade be replaced if it's too far gone? Can the teeth be resharpened?
Replaced? Most likely if you can get the part and have the skills or know someone who has the skills. Several of them right here on AAPK could do that job.
Sharpened? Yes. If you can sharpen a hand saw or know someone who can. Same process.

[giovanni8]

Jerry D & Iron Hoarder, thanks for the follow up & welcoming words.
Yes, I will post pix soon as I can get them spiked offa' the e-bay site. They're not so hot to begin with but it's something to work with.
Yes, I use this stuff called Kroil on rusted & frozen parts. It penetrates and frees up stuff that goes back to the dinosaurs. But I don't want to stain the plastic handles either. I'll try to see how bad it is and work with the least invasive method first. Yes, PB Blaster works real well also, we use a lot of it but it's kinda like diesel fuel on the plastic. I plan to try & unscrew the handles if the screws are grippable with a slotted screwdriver. They looked a little rough.
But yes, I'll try that polishing compound.
I'm thinking also the blades could be buffed out on a jewelrs wheel with light gauge rouge, but that's all going to be determined by the shape it's in when I open the box.
Thanks again for the follow up, we'll talk more, regards, Giovanni

[tjmurphy]

The best penetrating oil that I have ever used is the old style automotive brake fluid, which I think is mineral oil base.

[gino]

Welcome !

[TripleF]

to AAPK

[giovanni8]

OK, here are a couple of pictures- they're not the best quality, but I will take a coupld more when I receive the knife. I plan to do something like a before & after & along the way profile- this tool may need surgery to save it. This is going to be a user tool, not a wall hanger. By 'User', I mean to peel an orange or open an envelope.

The saw blade is still stuck inside. Will need to do delicate extricative operation to pull it out.

The nice people at Bear River knives in michigan gave me a little info on this as well - they said the kinfe sold for @2.95 when new, probably around 1944. Thanks for the comments & advice so far. We'll know pretty quick how this will proceed.

Jack Knife 1.jpg (31.66 KiB) Viewed 5459 times

Jack Knife 2.jpg (38.27 KiB) Viewed 5459 times

[jerryd6818]

The handles remind me of that "hard rubber" material the British put on their military knives. It will be very interesting to see what you get and what you do with it.

[Miller Bro's]

This is going to be a user tool, not a wall hanger. By 'User', I mean to peel an orange or open an envelope.

It is awfully big and heavy for those jobs. If you have never owned one of these before you will see what I mean when you get the knife in your hands.

I have a couple of these they were originally gun blued, all metal surfaces, bolsters, blades, springs, etc.

The handles are black plastic, they can be taken off and cleaned, if the screws strip you can easily replace them at a hardware store.

Good luck with it and

[Owd Wullie]

Kroil is GREAT stuff!! STINKS to high heaven, but I doubt it will hurt anything on that beast.

Put a few drops in the joint where the saw blade hinges, stand it with that end down a few days and none of the KROIL should get on the scales that way.

Like Miller Bros said, that is LARGE hand full of knife.

TJ may like brake fluid, I've never tried it. I do know that DOT 3 stuff is hygroscopic and will attract and hold water. DOT 5 which is silicone based won't. "Back in the day" we used cheap ATF thinned with diesel for a penetrating oil. Then we discovered KROIL THE OIL THAT KREEPS!!!

Keep us posted on how it goes.

[giovanni8]

Got the knife today. It's not all that bad but has a couple of structural issues. The saw blade came loose on its own, no distress there. I need to check the dimensions though, it looks like it might have lost a bit of the tip thru the years.

The steel on the sawblade is in fantastic shape. The main blade has some discoloration that should polish out.

Spring action is very strong on the saw blade but less than tight on the main blade. Handles came off easily. There's a hefty pivot pin right amidships that looks like it needs tightenting and may put the jack back into the jack knife. The brass lock lever is tight and does its job.
The thing weighs almost one pound. Big ole' gnarly tool. Pretty good edge on the blade after all that time.

I'm really impressed with it. Pictures coming soon showing the restoration.

[giovanni8]

Couple of pictures from today- I took the plastic handles off and pressure washed the knife body. It cleaned the interior and blew all the gunk out of the body.
Then sprayed it with WD 40 to displace any remaining moisture.

The main blade spring action improved a bit, but that side rivet will need some work. there is a bit of play in the side bolster. To do this, the steel knife body will be positioned in a vise (non-marking jaws) and will squeeze it back into position.

Then depending on if it stays in position, I plan to lightly peen the rivet to keep it positioned in the hole. Simple process, just need to be careful with alignment and centering a punch on the rivet.

Plastic handles have some marking on the inside. Screws are in very good shape, came out freely.
I received an e-mail from Frank Trzaska, who runs a very impressive web site exclusively dedicated to Military Knives:

Frank writes:
The knife was made by the United Machine Tool Co. in Grand Rapids Mich. It should have the makers name stamped above the GR Mich stamping.

They were a secondary supplier to the military during WW II with this knife. They produced 60,000 of them during the war. They also sold commercial versions after the war with the parts chrome plated.

Parts are non obtainable for these knives. If you want to restore one the best bet is to buy two broken ones and make one out of it.

Thank you for the kind words on my site!

All the best
Frank Trzaska

Picture shows the saw blade tip has been broken, maybe 3/8 of an inch missing. The teeth are still fairly sharp and as mentioned, the sawblade is in very good shape with minimal to no discoloration.

Tomorrow I plan to polish the exterior and see what it looks like. I might touch up the blade but it's going to lose the blacking. Such is the sacrifice we need to make to clean this up to cosmetic grade.

[Miller Bro's]

It should look like this when you are done