All About Pocket Knives

I modded an old two-blade #62 Western Hunter recently removing the clip blade and then slimming the handle and blade down overall. A problem has arisen replacing the old pearlite covers with new faux ivory zumba covers. They came pre-cut (roughly 1.5" x 5" x 1/8"). The surface of the blanks appeared to be even. I've had a difficult time in the past getting covers to fit without any gap bolster to end cap on other mods in the past but I thought I nailed it on these. But as you can see in the photo there's a gap from scale surface to cover! I didn't touch that side of the Zumba and, like I said, the surface seemed level. One other detail: there was a very slight bowing of the zumba that I left while fitting the handles. They fit well otherwise and If I pressed on them the gap disappeared and I thought after gluing and then pinning them down the gap caused by the bowing would disappear.

So are we looking at an uneven surface here, or bowing or both? I'd appreciate any help I can get eliminating the unsightly gap next go-round as I plan on giving it another shot. Thanks in advance!

It appears to be an uneven surface in the handle material. Did you try to flat sand the handle material before you installed it? You might be able to close the gap by tightening the pin but you risk breaking the handle.
Jeff

There could be a couple things happening here...

It looks like the bolster is not fully attached to the liner. That could just be the manufacturing method. I always check these when I take things apart, and solder them down if they might have a gap. This may a be a nothing burger though.

How did you prepare the material to glue to the liners? Did you rough up the surface so the adhesive would have something to adhere to? Are the pins for the material holding or have they pulled at all? After you glued and sanded material down, did you check the flatness of the liners? With some materials/glue, when the glue dries, it will actually cup the liners out of flat.

Lastly, did you sand with any type of power sander/belts? Excessive heat can cause micarta/synthetic materials to change shape.

Based on the pic, I may be leaning toward bowing of the material causing that.

I recently picked up some faux ivory handle material...that I haven't used. I don't remember what company or brand...but this weekend, when I went in to my box of scale material...it was all distorted...like it has somewhat "flowed" like taffy. Obviously, not to that extreme. It is stored in my bedroom closet, so it wasn't subjected to extreme temps...but...it was the only scale material exhibiting distortion. Did you use clamps with epoxy, attaching the scale to the liner? I always epoxy and clamp the liners overnight...before I pin. Seems sometimes, the scale will lift a little, in these areas...without clamping. Just my LIMITED experience.

Thanks for the suggestions. Based on what you've said I plan on trying again but checking first to see just how even the downside surface of the material is.I also want to see if I can find anything written about this particular substance and find out if it reacts to glue by warping. I realize now that gluing the scales down requires the correct epoxy and clamping and not a few drops of super glue spread across the surface. Frankly I do this because I don't quite trust my pinning. I know the manufacturers of these old knives never glued first. I'm thinking if in fact Jumba has a tendency to warp clamping the covers down over night should counteract that. Again-- thanks!

Albert Einstein said the true route of all knowledge is experience.
You learn by trial and era.

I would try it with no glue next time.
After the glue dries you finish with machine sanding.
If you create too much heat with dense material the epoxy expands.
I was like you and glued everything.
If they didn't use glue when it was made I wouldn't when re handling either.
If you peened enough handles they should hold forever with normal use.

"anything hand made isn't perfect anyway"
I think your knife looks fine.

knives-are-quiet wrote:Albert Einstein said the true route of all knowledge is experience.
You learn by trial and era.

I would try it with no glue next time.
After the glue dries you finish with machine sanding.
If you create too much heat with dense material the epoxy expands.
I was like you and glued everything.
If they didn't use glue when it was made I wouldn't when re handling either.
If you peened enough handles they should hold forever with normal use.

"anything hand made isn't perfect anyway"
I think your knife looks fine.

Sage advice--thank you. This combined with what I've gleaned from the comments above is exactly what I need going forward.

If you used CA adhesive to attach the handles before pinning them, that in itself might be the problem.
There are two things I have experienced trying to use CA, which is frankly why I don't use it on handles, especially synthetic materials. The first problem is CA can cause some distortion of some materials, I've only noticed it with plastics and it's not real common but I have encountered it. The other problem I have encountered is that sometimes the CA will dry quickly and you will have a drop of dry CA that holds the handle above the liner, preventing them from being pulled down tight when they handle is pinned.

Just a couple more possibilities.