Epoxy Granite Pouring Question

I’d love to hear from @langmuir-daniel on this, but open to all ideas. I know LS is cagey about sharing too many instructions for EG, but this is rather basic:

I’m prepping to pour my EG mix on Monday. The epoxy binder I’m using (Mas Deep Pour) has a 0.5 to 1" recommended pour depth when used on its own (no filler) to avoid overheating from exotherm. I’ve only poured small test batches, which had very little exotherm (especially compared to similar sized cups of pure West System epoxy which get very hot to the touch). My intuition tells me, there is much less epoxy per unit vol, and more thermal mass to absorb exotherm, so I should be able to pour EG deeper than 1".

That gets us to the question at hand: does Langmuir pour the full ~4 inch depth of the tray at the factory as a single dispense, or do you guys pour it in steps?

Hopefully you can just let us know the broadest strokes of what you do, with the understanding that your binder and filler system is certain to differ. I know I’m off the usual path here, and won’t hold LS responsible for my results if things go wrong!

I called Mas Epoxy and they told me I should step pour in 1 inch layers… but I’m not sure if this was just a “give the customer the safest possible answer” deal, or if it has any real relevance to highly filled EG with only 15% binder.

Other data points / notes:

  • The Mas Deep Pour epoxy is already a very slow setting system. I’ve seen Youtube videos of people tamping fairly large EG pours all at once with West System binder, which is almost certainly a faster curing binder. However, they are all fuzzy on the timing details.
  • I’d really rather pour all at once (or in faster intervals) to ensure better bonding & cohesion.
  • The safest path would be to pour a first 1 inch layer and chart the temp with a thermocouple. I will do this and post results regardless.
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Can I ask why you are pouring epoxy so deep? Concrete is a 1/16 the cost?

I’m pouring epoxy “granite” (actually epoxy-silica). My mixture is about 15% epoxy by weight.

The main reasons are:

  • Better longevity vs concrete, lower susceptibility to damage from freezing shop temperatures or mechanical shock (for example, if I want to transport the machine someday).
  • Better vibration damping
  • Not that expensive, since a decent % of the volume of my casting will be taken up by a 30mm solid granite offcut slab I salvaged.

Secondary reasons:

  • Allows me to cast my table with extra integrated features, with traditional mold techniques I’m already familiar with
  • Faster, no wait for a topcoat epoxy pour as with concrete (although I’ve now spent 4 months tooling around on my build in off hours, so this one’s a stretch lol)

It looks like Langmuir is happy to ignore posts like these, so I’ll just have to forge ahead tomorrow with a step pour. Disappointed!


Hello, I’m considering EG at this point because I intend to move the machine in six months or so. What did you end up doing and how did it turn out? What would you do differently if you were to do it again?

I did contact LS and they told me they use 12% clean sand and 88% epoxy, which conflicted significantly with a link they gave me describing how to mix EG. I think they reversed the numbers to me by mistake.

Thanks for your help.


What did they say when you pointed that out?

I just alerted them today. I haven’t received a response yet. I will update once I do.

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Here’s the link they shared with me:

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@maluco They almost certainly meant 12% epoxy, 88% sand, by weight. The opposite would be totally bizarre and pointless.

My epoxy granite build went well. Here’s a thread with some pictures of the outcome:


Response was quick and clear-

“I meant to say 88% clean sand and 12% epoxy. That should be much closer to what the link suggested. Our ratio will be a little different since we don’t recommend using gravel.”

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Thanks for sharing. That is a super machine you e built. That’s very exciting! Well done.

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