INTARSIA - a walk through my first piece

Pat Yes, that would work too, but you wouldn't have very much glue area. It would be better than no side pieces, but I think having a back would be better.

are you putting on the backing last? Thinking out loud here - I wonder if it would work to do the front construction, lap the back flat, glue on soft material, grind it really really thin on the lap (like almost see-through thin), then build your back pattern separately, lap it flat, and glue to that.

This is what's fun about intarsia - you can get really creative with what you make and how you attach it.

In our class, which was just a quick afternoon class, the teacher built the piece first, ground teh front flat and tidied it up, and then covered the back with steel epoxy. Which you then have to grind down flat. Essentially a backer. But messier. Lighter though. I think I'd prefer to use a proper backer.

The epoxy glue is stronger and more durable than the stones. Why is a back needed? Aren't the stones strong to enough to be a cabochon on their own?

Never made intarsia and never would have used a backer if I did. Just spit balling here.

Very nice work! Thanks for the tutorial. i have been thinking about branching out into intarsia myself and I have an Ameritool to work with.

For white rock I use the opaque white agate from the polkadot agate mine, takes a great polish.

Rockoonz
Bluesky78987

Anyone else make an intarsia piece?
Could you post photos of the intarsia you have done? It would be instructive.

OK found another, it was my class project in the class I took in 2013 at the rockhound retreat.

Pat - sure, will take some pics in a few. I've used Howlite on a couple of them. Why would they say Howlite is too soft? It works great and is cheap and readily available (especially here in CA). One piece I have Howlite next to black jade from australia next to pinolith. No undercutting problems and it's non-chippy and easy to cut match sticks from. Polishes great too.

@shotgunner - You need a backing of some sort because the surface area you're gluing is too small for long term strengh. This is an exaggeration, but it's like gluing two 2x4s toghether end to end. Some of the pices are really thin (front to back of the piece). While it's strong in tension, it's weak if it were to encounter bending forces. Back it, and now your glue seam is going to resist the shearing forces of bending (as well as whatever stiffness the backing stone has).

(Deleted post - looks like I killed the thread, soooorrry.)

Hello, I’m new to the forum and was perusing the posts and came across this interesting Intarsia discussion. I’ve been making Intarsia and also teaching classes for a number of years. Regarding the super glue and backing discussion... I love super glue for building intarsia as it dries quick and makes a strong bond. However using it alone has 2 major disadvantages. First it is very brittle and simply dropping your constructed piece on a hard table top (not to mention the floor) COULD possibly result in sufficient jarring to cause one or more joints to come apart. Second, super glues (cyanoacrylates) will eventually break down with exposure to water/moisture. The solution is to attach a backing with (clear) epoxy then it will never come apart.

If you have a piece that’s interesting on both sides such as in some picture jaspers, a solution I’ve had a lot of success with is to attach the final bordern with epoxy.