Tapping threads in G-11 garolite fibre board

Yep.

Should I epoxy it together?

Not necessary, but it might help the long-term dimensional stability of the base.

Make sure your drills are perfectly sharp, and drill at high speed with a fairly low feed rate (but DON'T dwell in the hole) or the material and the bit will burn. We used to drill FR-4 at over 350fps, and about a 1.5mil/rev feed rate. HSS bits would usually last about 20" of hole depth before they started burning.

Make sure your tap is spankin' new and razor sharp. Plan on re-sharpening it or throwing it away after the job. Don't do full-profile threads... 75% works fine, and won't ruin the tap quite as quickly. That stuff is horribly abrasive.

Carbide tooling is the way to go, but pretty costy for a one-off.

LLoyd

I've made assemblies of G-10 a couple times, but used thread inserts epoxied in place when concerned about failure of the threads in the composite.

Ned Simmons

If you're planning to open and close it more than once, go with threaded inserts or "pop rivet" inserts (uses a tool kind of like a pop rivet tool to put in threaded inserts with soft aluminum collars - don't know it's proper name - they use them on circuit boards sometimes). Fibre board won't hold normal threads more than a couple cycles of use.

Thanks for the tips.

stan

According to Jim McGill :

It sounds as though you are describing rivnuts. Originally by B.F. Goodrich, now sold by someone else, IIRC. You can sometimes get the genuine B.F. Goodrich installation tools from eBay auctions. I got all of mine that way -- but they had more back then than they seem to have now.

And -- it will abrade the screw threads (as well as the drill bits and the taps when the threads are being made).

Enjoy, DoN.

Karnuts or Kasnuts.

I picked up a full set the other day at Reliable Tool for $10. 6-32 through 5/16-18. All the insert tools and the adapters, probably a hundred of each size inserts. I thought I did ok.

Gunner

"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences."

- Proverbs 22:3

Hmm ... yet another style. Do they work like pop rivets too?

There are also keenuts (or is that keynuts) -- whatever the name, they are an alternative to Heli-coils; The outside thread does not have to match the inside, so normal taps work, and it has a small flange to keep it from going too deep, after which two (or four, depending on the size) projections are driven down into grooves at right angles to the threads, cutting matching grooves in the threads into which they are mounted. Those would probably be the best bet for going into thick Fiberglass -- G-10 or whatever.

No -- you did a lot better than OK. :-)

Enjoy, DoN.

Don't forget to put the sholder side of any nut like this on the far side of the work so that the bolt pulls the shoulder into the material. I've seen idiots that have put the shoulder on the same side and considered it to be the right way to go for the job. IF you want a spece, put a spacer or washer in there!

-- Yeppie, Bush is such an idiot that He usually outwits everybody else. How dumb!

I messed up at a surplus store and only bought two boxes (1000/box) of 6/32 Rivenuts. They had hundreds of boxes for 50 cents each. :(

Sorta. They require a two piece tool The main body of the tool holds a serrated gizmo that bears against the face of the "nut". Then an inner tool with a stub allen is used to screw in a socket head cap screw of the proper thread for each "nut" and as you turn the capscrew, it pulls the back of the "nut" either into a mushroom, or in the case of the bigger ones..breaks a cone shaped wedge off the back of the "nut" and into the body..swedging it in. The body of the "nut" is smooth, the larger ones smooth and wasp waisted.

"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences."

- Proverbs 22:3

Ohh!! Those would have been nice. Were they blind or through-hole versions?

Enjoy, DoN.

Through hole, and they had the threaded studs to install them with a pop rivet gun. I think I still may have about half a box left. They were used on a lot of screen doors and windows at one time, so lots of friends fixed their doors and windows, instead of having to buy new ones, as one box disappeared, and part of the other door. They decided that they really did need a drop of oil on the screw threads, after that.

That will work, but if you have a lot to install, the BF Goodrich speed tools are a *lot* better. (Even better are the air-powered ones, but I don't have that, and I do have the speed-tools.

Yep!

Enjoy, DoN.