Ulster repair help

[CarMan]

I got this knife because I wanted to try and repair it. But, I have a few questions if anyone that does this is willing to help. First off what I need is a back spring, but I don’t know how to make one so I am thinking of looking for a trashed donor knife. I know the knife needs cleaned, but thanks to a friend I now know how to do that. My goal is to make it look like nothing has ever been done to it (not to sell, just for my collection).
My questions are:
1.) Do I use a dremel tool to grind off the top of the pin and push it through or do I try and drill the head off?

2.) How do I go about finding the right size pin to go back in?

3.) How do I round off the pin head properly and hopefully without marking up the bone scale?

4.) Do I need another Ulster with the same tang stamp to make sure the spring fits or can I use a newer Ulster spring from a scout/utlity/engineers knife?

Thank you for any & all help.
John
Ephesians 2:10

[ea42]

You can use a dremel if you have a very steady hand or you can dremel a flat spot and then drill it out the rest of the way. Use a bit that's just a hair narrower than the pin head. That way the head will drill off and you can push the pin the rest of the way. You're going to have to remove the bolster pins too and disassemble the entire knife. I'd take one of them out before you remove the center pin to relieve the pressure on the remaining spring. Makes pushing that pin out easier. You can remove those with a razor blade from a utility knife. Wedge the utility blade between the knife blade tang and liner and hammer it through the pin. Be careful not to mar the bottom of the knife as you're hammering.

My guess is that you'd probably have to find a spring from that same era as later ones might have had some modifications to the design. Not positive on that though.

The center pin is likely around .086 or thereabouts. If you have a caliper measure the width of the one you pull out. I probably have a replacement here I can send you.



Eric

[BIGHEAD]

I usually use a dremel and burr the top of the pin off then take a small nail set and knock it through. The pin is probably a 5/64” or 3/32”.

[Mumbleypeg]

Several tutorials on disassembly and repair of pocket knives here viewforum.php?f=38. You will likely find some helpful tips, and answers to your questions in posts there.

Ken

[Reverand]

All great advice.
You can get brass pin stock at some hardware stores, and in good craft supply stores. I have found some at Hobby Lobby before. As was said, measure the old pin once you remove it, then buy a piece of pin stock.
The silver nickel pins are harder to find. I always have to order those. Jantz and other knife supply companies carry silver nickel pins, but shipping can be expensive. Sometimes I come out better on small batches to order off of eBay.
There are some sticky threads on here dedicated to sharing where we find pin stock.
If you cannot find the exact size, cut off a 3-or-4-inch piece, chuck it up in a drill and use a file & sandpaper to spin it down to the correct size.
Also read several posts and watch tutorials on peening. It is not that difficult, but you may want to practice on some other knives if that one is important to you. I did several knives in wood handles, but still I cracked the first few that I did in bone.

[Bill DeShivs]

First, it's doubtful you can make the knife look new.
Second, you don't have to remove the blade pivot pins to replace the backspring. Just the center pin.

[CarMan]

Thank you everyone for your help. I am hoping to get a few junk knives to practice on before doing this one after reading all of this. Again thank you very much for the help.

[CarMan]

First, it's doubtful you can make the knife look new.
Second, you don't have to remove the blade pivot pins to replace the backspring. Just the center pin.

This is what I was hoping to hear. I know it won’t look new, I just don’t want it to look cobbled together when I’m done. Thank you

[CarMan]

You can use a dremel if you have a very steady hand or you can dremel a flat spot and then drill it out the rest of the way. Use a bit that's just a hair narrower than the pin head. That way the head will drill off and you can push the pin the rest of the way. You're going to have to remove the bolster pins too and disassemble the entire knife. I'd take one of them out before you remove the center pin to relieve the pressure on the remaining spring. Makes pushing that pin out easier. You can remove those with a razor blade from a utility knife. Wedge the utility blade between the knife blade tang and liner and hammer it through the pin. Be careful not to mar the bottom of the knife as you're hammering.

My guess is that you'd probably have to find a spring from that same era as later ones might have had some modifications to the design. Not positive on that though.

The center pin is likely around .086 or thereabouts. If you have a caliper measure the width of the one you pull out. I probably have a replacement here I can send you.



Eric

I do have a old caliper in my box. I will see what it measures at & double check size against the same size drill bit. Thank you for the help it is very appreciated.

[CarMan]

I usually use a dremel and burr the top of the pin off then take a small nail set and knock it through. The pin is probably a 5/64” or 3/32”.

Great, I have plenty of nail sets. Thank you

[CarMan]

All great advice.
You can get brass pin stock at some hardware stores, and in good craft supply stores. I have found some at Hobby Lobby before. As was said, measure the old pin once you remove it, then buy a piece of pin stock.
The silver nickel pins are harder to find. I always have to order those. Jantz and other knife supply companies carry silver nickel pins, but shipping can be expensive. Sometimes I come out better on small batches to order off of eBay.
There are some sticky threads on here dedicated to sharing where we find pin stock.
If you cannot find the exact size, cut off a 3-or-4-inch piece, chuck it up in a drill and use a file & sandpaper to spin it down to the correct size.
Also read several posts and watch tutorials on peening. It is not that difficult, but you may want to practice on some other knives if that one is important to you. I did several knives in wood handles, but still I cracked the first few that I did in bone.

Thank you for the advice. I’m a little worried with this bone being pre WW2, it’s kinda old. I will definitely look up peening.

[CarMan]

Several tutorials on disassembly and repair of pocket knives here viewforum.php?f=38. You will likely find some helpful tips, and answers to your questions in posts there.

Ken

I will spend a lot of time looking this over, thank you sir.

[ea42]

First, it's doubtful you can make the knife look new.
Second, you don't have to remove the blade pivot pins to replace the backspring. Just the center pin.

Bill I'm an idiot LOL! A blade on each side. I've only been building knives for over a decade, sometimes I'm pretty dense.

CarMan disregard what I said about removing the blades, totally not necessary.

Eric

[CarMan]

First, it's doubtful you can make the knife look new.
Second, you don't have to remove the blade pivot pins to replace the backspring. Just the center pin.

Bill I'm an idiot LOL! A blade on each side. I've only been building knives for over a decade, sometimes I'm pretty dense.

CarMan disregard what I said about removing the blades, totally not necessary.

Eric

No problem. Thank you for clarifying, much appreciated.