Yes, another epoxy/resin/filler question

[Jim Grieco]

I mix my best guess at enough to do the whole thing.... but it's OK to mix small amounts too if you're not sure on consistency etc or want to take your time or practice. My method of applying the goop is crude and quick, just a couple of minutes to apply it. I just use a giant popsicle stick and shove it in the gaps. Make sure to mix it thick enough that a big dollop of it will stay attached to your stick and not drop off. I apply it with the vase on the lathe - inevitably some of the epoxy will end up on the underside and you don't want it to sag out of the gaps. My pattern pieces are usually only about 3mm thick too so the depth of the epoxy is only 3mm.

Oops, first attempt was a disaster! I was worried about mixing too much cabisil so I used too small of measurements and it started setting before I was done. Lesson learned!
Anyway, I'm thinking about using the sawdust from my collector. Is that too fine of a filler? Also, will the black mica mask the color (tan) or will it look like I have fine sprinkles?
*That cabosil really grayed up the first attempt

 

[Paul Paukstelis]

If you have access to a fairly large 3D printer perhaps you could model and make a fairly close fitting mold? I'm not sure how big that piece is but a multi piece mold with taped seams seems like it would work but I may be delusional. This would be easy to pour into with minimal waste. Hmmmmmmm this is giving me some ideas on using resin.

See my thread in the Projects forum.

 

[Steve Bonny]

Oops, first attempt was a disaster! I was worried about mixing too much cabisil so I used too small of measurements and it started setting before I was done. Lesson learned!
Anyway, I'm thinking about using the sawdust from my collector. Is that too fine of a filler? Also, will the black mica mask the color (tan) or will it look like I have fine sprinkles?
*That cabosil really grayed up the first attempt

Hehe, yeah I dump that stuff in. Sawdust is fine. Fine dust from a sander works best for me but I have also used a mix of coarse and fine. You could sieve it too to get the coarse stuff out. I'm not sure I understand what you are going for for color? You mention the cabosil turned grey. Tan and black mica? What are you going for?
For colour I usually just add an alcohol stain. If you're getting grey instead of black, add more black stain. I've never used mica, so not sure what you'll get.

 

[Jim Grieco]

Hehe, yeah I dump that stuff in. Sawdust is fine. Fine dust from a sander works best for me but I have also used a mix of coarse and fine. You could sieve it too to get the coarse stuff out. I'm not sure I understand what you are going for for color? You mention the cabosil turned grey. Tan and black mica? What are you going for?
For colour I usually just add an alcohol stain. If you're getting grey instead of black, add more black stain. I've never used mica, so not sure what you'll get.

So the sawdust does not affect the color?
Mica powders are common with resin so I just went with that. I achieved the black I wanted when mixing but the resin set up gray. Just wondered if the cabosil had something to do with it.
Thx

 

[Steve Bonny]

So the sawdust does not affect the color?
Mica powders are common with resin so I just went with that. I achieved the black I wanted when mixing but the resin set up gray. Just wondered if the cabosil had something to do with it.
Thx

If you are after black finish, I would add a stain or dye. Mica may not be fine enough? As mentioned, I've never used it. Wood dust colour will impact the colour of the epoxy but I just overwhelm it with black stain. Wood colour becomes more important if you are going for a lighter colour. Either Cabosil or wood dust will come out very black if you add black stain. A trial is always a good idea!

 

[Steve Bonny]

p.s. I use either Chestnut Spirit stains or Colortone concentrated liquid stain. Either will get your epoxy very black and both appear to be compatible with every epoxy I have used so far.

 

[Jim Grieco]

p.s. I use either Chestnut Spirit stains or Colortone concentrated liquid stain. Either will get your epoxy very black and both appear to be compatible with every epoxy I have used so far.

2nd attempt went a lot better. I googled for the ratio of mica per ounce and figured out from there. The color came out a deep espresso which I like even better! I also used sawdust and not the Cabosil and it mixed right up.
It has been over 2 hours and still not set up completely. Moving as fast as a glacier but still moving. If I were to do it again, I would use much thinner pieces. I think gravity is using the weight of all that resin and pulling at it. Plus, who knows at this point how much is staying in all the crevices. I'm sure I'll have some filling to do.
I hope it cures within a decent timeframe!
I ended up mixing 24 oz each of resin/hardener, 3 1/4 tsps. of mica and 7 cups of sawdust. I had a little bit left over but not much.


Thanks for your help!

 

[Steve Bonny]

2nd attempt went a lot better. I googled for the ratio of mica per ounce and figured out from there. The color came out a deep espresso which I like even better! I also used sawdust and not the Cabosil and it mixed right up.
It has been over 2 hours and still not set up completely. Moving as fast as a glacier but still moving. If I were to do it again, I would use much thinner pieces. I think gravity is using the weight of all that resin and pulling at it. Plus, who knows at this point how much is staying in all the crevices. I'm sure I'll have some filling to do.
I hope it cures within a decent timeframe!
I ended up mixing 24 oz each of resin/hardener, 3 1/4 tsps. of mica and 7 cups of sawdust. I had a little bit left over but not much.


Thanks for your help!

Glad you are getting it figured out Jim. When I have had glacier issues, I rotate the lathe a quarter turn every couple of minutes. Not sure if it helps much, but made me feel like I was doing something useful

I always end up with pits and cavities. After turning and sanding to finished size, I always end up putting on a second layer of epoxy. This is usually a lot easy to apply.

 

[Wyatt Holm]

Here's some links that might help

Superior Knife Grade Polyester Adhesive

Buy Superior Knife Grade Polyester Adhesive online from GranQuartz - the preferred distributor for stone fabrication, equipment, and supplies since 1971.

www.granquartz.com