Arbor press and bolster pins

Can an arbor press be used to mushroom the bolster pins? Hammering the pins gives me about a 75% success rate and I'd like to find a method that is more consistent. Any advice will be appreciated.

Here is the method I use. has cupped dies top and bottom to spread the pins.

What do you mean by success rate? Are they falling off or loosening up? How exactly are you prepping your bolsters and pins?

By success rate I mean sometimes the pins are showing when I finish the bolsters. I peen with a hammer and just beat the snot out of the pins. If an arbor press would work it sure would simplify things.

I've been trying to figure that one out for years (pins showing in bolsters), and still don't nail it 100% of the time. I've used hammers, presses, and even tried my forging press a few times. Hopefully someone will pop up with a sure fire answer for never having the pins show, but it seems that "Mr. Murphy" is alive and well....and most times he out stays his welcome in our shops!

Well I am still very new at this game but what I do is whenever possible I try to mushroom one side of the pin before I insert it. To me the pin is mostly there for shear forces and the epoxy I am using does most of the holding. I will rough up the center of the pin and I usually make a slightly larger hole in the in the handle material on the backside at that point. That gives me a pocket of epoxy that will bite to pin/rivet. It also give me an area for expansion or bending of the pin if the forces exerted on it by peening cause it to distort.

I like to give to use slow curing epoxy and will do the peeing after hardening but before it achieves 100% hardness. That way if the pin does bend ever so slightly it shouldn't cause any separation of the handle. Cutting the pin so that you only leave an 1/8" or less helps to insure you will have enough to peen without causing distortion of the pin itself.
I usually make a countersunk hole in the handle material for the rivet/pin to be peened into. I made a rivet spinner out of a nail set. I cupped the head with a drill bit and hardened the point.The spinner I made will help to get them more round but you still have to use a small Ball Peen Hammer to finish the job. Slow and steady taps and make sure the backside is supported

I saw a jig someone had made on one of the knife sites and I think I will try to make one.I wish I had saved the pic but I didn't. It had a raised pin to act as backing for the pin that is being peened, it also had a padded adjustable screw that could be raised or lowered to basically level the handle so it would be level when resting on the post for the pin being peened. It has also had a padded clamp the could be adjusted to height so the the handle material could be clamped, leaving both hands free to the riveting/peening on a pin.

If there is and easier/better way I would love to learn it, as like it has been said this is always the step that put my nerves on end. I mean to be that close to finishing a knife and then screw up the pins in the handle or the handle itself is very disheartening to say the least!

I just getting back into knife making, and dont have a lot of experiance with this. having done some research on this, Ive read that using a tapered reamer in your hole will help, as it shapes a cone shaped hole thru the bolster that allows the pin to "swell from the bottom of the hole, upwards theus pushing against the bolster.

One question, are bolsters usually glued in place as well as pinned? I figured this would give more room for a line to show in the fit up.

Thanks and God Bless
Mike

I Think The Late Great Bob Engnath had a tutorial online somewhere showing how to make a precise peening jig. Probably a Google search would find it! I still do mine with a ball peen hammer and a tapered reamer for the countersink. Using pins & bolster material from the same supplier helps some plus keeping everything super clean before assembly. The only thing the glue does is seal out moisture, I use thin super glue wicked into the joint after the bolsters are peened. Just one way of doing it, not necessarily the best for some.
Thanks for reading my opinion!
Sincerely,
Clint

Ed, just in case you ever need to get in touch with him, "Mr. Murphy" resides full time in my shop.

Chall,
Others have already mentioned what I was going to ask: Do you use a tapered reamer in your pin holes before you peen? You might try that and see if you have any more success.
And I'm sure this goes without saying, but you want to make sure to use the same type of stainless steel (or whatever other material you may use) for your pins as you do your bolsters.

Yes, I do use the tapered reamer and things seemed to improve when I started using it. In reading all of the comments the one thing I probably don't do as well as I should is clean the pins and holes thoroughly before I peen. I will give that a try...thanks for all the input.

I just got through building a pin press, but it was a waste of my time. It doesn't come close to giving enough pressure to "smash/squeeze/expand" the pins. I only used a six ton bottle jack. I probably should have gone with a much bigger one. The other problem I found with it is I can't keep the pin vertical under the press. It just wants to squeeze it outwards and slip off the pins.

I have always had good luck with using a hammer and small anvil. The only reason I wanted to try the press was because I sometimes get "ballooning" on the face and back of my bolsters (I typically only go with 1/2" width bolsters, which is kind of narrow) when I don't strike right on target.

My method is this: I don't ream the bolsters. I apply JB Weld the the knife (keeping away from holes) and attach my bolsters. The JB is just a sealant and a good indicator of how tight you are getting your bolsters to the tang. I have found that when I thought they were tight, I put a few more hits on it and more JB sqeezes out. I also use small vise grips to pinch the top and bottom of the bolster material while peening to get them as tight as I can to the tang.
I made a small hardened plate with I think 1/4" demples in it to start the peening process of my pins. This allows the top and bottom side of the pins to start mushrooming at the same time. I lightly do this alternating sides. Once the pins are mushroomed the same on both sides, I use the vise grips to pinch the bolsters tight and start peening and keep alternating the sides. Once I feel they are tight to the tang, I then use a small handled 2lb "sledge" and hit the bolsters flat on the anvil to really smash them in (pins). When I am done, The pins are pretty much mushroomed to nothing, just flakes of metal.

This works great for me. But like I said, I just run in to the faces "ballooning" sometimes if I slip up just a little.

Do a google search , Fighter step by step.Charles Vestal shows how he pins his guard.Taper the holes dome or taper the pins a little.I use a hammer then the pin press.

Works great Rick

I do it totally different than you do. I clamp an oversized piece to the blade and drill the holes. I then take the second piece and clamp it to the first drilled bolster. I use 3/32 pins and after both sets are drilled, cut my pins material. I drill with a 40 drill bit. I then put pins in both bolsters and put the blade on top, with the pins through the holes in the blade. I mark the curviture of the front of the bolster and grind to shape I need. I square the back or mating surface of bolster to handle material. I take the front of bolster up to 1000 grit and buff. I have the surface of blade at 1000 grit. I take bolster to flat and sand the mating area of bolster and knife to 1000 grit. The drilling of bolsters will punch out a little mound that needs to be removed. I take a tapered 3/32 reamer and ream from the outside surface to blade area.
I take the pins and point them a little bit and clean with acetone. I put everything together and use needle nosed grips to clamp everthing together and straight. I do have a pin press and mushroom the end pins but you can hammer them the same way. I do not use any epoxy but have wicked some super glue to the edges if it is going to be a hard use but most times don't.
I ,after pins are mushroomed, take it to a block and give each pin a solid smack to flattn.
The needle nosed grips insure that the bolster do not move while you are mushrooming the pins. I have basically a solid piece of steel at this point.

I will add when you use the tapered reamer, you are actually sucking that bolster dwon on the side of the blade, making an even better joint
This is what I wrote when Lerch was having problems with his first attempt at pinning bolsters.

Alright, here is my insaine way of making sure the pin swells..... When I put a pin in I hammer it bit. The grind away the excess because I dont have brains enough to cut them the right leinght to start with. The I rap them with a sharp center punch a time or two. The I hammer them out some more. Sand and buff. I have use this method with putting pins in a few dozen knives and all has worked okay for me.