Using Hxtal for stabilizing fractures in slabs & cabs

Thank you.    Yes, photos would be awesome. 

What is the viscosity of the mixed material like?  Does it fill cracks readily?  I assume it must or people wouldn't use it.  I have not yet purchased any.  The price scares me.  Which leads me to the next question- what is the shelf life of it?

Great! Thanks!

Looks great, thanks. I guess I know what I need to get.

I would definitely agree Tommy. I acquired mine the same was as Lynn did, From Helen. I still have half of what she sent to me (+ or - 1 oz of one and 0.5 oz of hardener) left and I have used it many times.

I mix mine two to one and apply without heat then let it set for a week. It will soak into the tiniest cracks and set up like the rock. To make sure absolutely none is wasted I always have an extra slab or piece of rough I want to us it on so if there is a little left over I cover whatever I can with it. I have worked on a slab six or seven times with the excess before it is finished but I consider that one a free one. The only negative I have is if the crack is a tiny bit wide the glue will run out the other side. Masking tape is your friend when using Hxtal
Jim

Very interesting thread y'all - the sticker shock also stopped me from using it, and I had a misconception that you had to use a vacuum pump with it. I'm all in on the "mix it up and paint it on" solutions!

When hardened HXTAL has a refractive index near that of most common types of glass. And it doesn't yellow with age as badly as many epoxies do. So it is a good choice for clear to slightly translucent agate or quartz, or other light colored stones. HXTAL and Opticon Fracture Sealer work best for treating tight fractures. But for wider cracks and gaps the less expensive two-part epoxy adhesives will work as long as you heat them up first to make them less viscous.

Epoxy 330 is a good water clear epoxy to use. And even some of the two part epoxies available at hobby stores can be used. I like the Bob Smith Industries brand. They make five, fifteen, twenty and thirty minute cure-time formulas. As a rule the slower the time cure formula the harder the cured epoxy is. And the slower the cure time the more time the epoxy has to saturate. I usually use the thirty minute cure epoxy. Heating the epoxy resins first does thin them so they saturate better but it also makes them cure faster than they do at room temperature. So you have to have everything ready and work fast.

To heat the two parts, if I only need a small amount, I use a scrap piece of window pane glass and just squeeze out the amount I need in two individual resin parts rows, spaced widely enough apart that when they start liquefying from heat they don't run together and begin hardening. I place the piece of glass with the epoxy on top of my leveled dop wax warmer and let it heat until it gets runny. Glass will not absorb any liquid from the Epoxy nor impart any contaminates into it. As the epoxy warms, the rows of resin will begin to spread. Once they have nearly stopped spreading it's time to mix them together and apply them to the stone. I do this with a 4" blade artist painting knife. Also it helps flow and saturation to have the stone warmed as well.

After applying the mixed epoxy to the stone be careful where you set it. The epoxy can seep through to the other side and glue your cab or slab to whatever is underneath. And if it's heated it can penetrate wax paper and adhere it, and the wax paper to whatever surface is underneath the wax paper (yes I learned this the hard way). So now for messier jobs I use wood shavings from my jointer or planner as a bed. Newspaper will work too. Either are easy enough to sand off if the glue seeps through but the wood shavings are easier to remove.

If I'm treating several stones and need a larger amount of epoxy than is practical to heat on a piece of glass then I use clean small metal food cans like tuna and salmon comes in.

Regardless of which type epoxy you use, a vacuum chamber can help with saturation. There are several posts and videos online on how to make one cheaply. I made the one for quick use using a plywood box and a small shop-vac for suction pressure. It worked okay but not as good as a chamber with an actual vacuum pump and valve that can hold vacuum pressure for longer periods of time will. I picked up a small vacuum oven cheap from a college surplus sale for this purpose but haven't gotten around to trying it yet.


Also should probably mention that I soak any slab or stone I'm going to treat with epoxy in lacquer thinner (not paint thinner) first to remove any saw oil residue.

I know a couple of master intarsia makers who use 10 minute epoxy, waxpaper, a toothpick, a heat bulb (in an articulating lamp) and get an entire intarsia completed in a couple of hours.
Sounds like this process it a lot more entailed.

Excellent Tommy! Looking forward to your results!

I put it in squeeze dropper bottles that I buy at JoAnn Fabrics or other hobby store.
I measure it out by the drop - 3 drops of part A to one drop of part B.
Perhaps my drops aren't too precise since one part is thicker than the other.
When I initially got it from Helen here on RTH, the ratio was 1:2. She said it was the same Hxtal, even though it used a different ratio.
I've never mixed enough to do it by weight.
A guy I met at the Denver show uses a vacuum and doesn't use heat, but lets it cure for a week or so.
I'm going to try that method & see.
Lynn