[Katherine Swift]

This question comes through email:

i’m making some tests with epoxy.

May be you can tell me what is the problem with my test ? There is a sort of blotch on my epoxy.

Thanks in advance.

 

[Katherine Swift]

It looks like you poured resin directly onto this surface? i.e. this isn’t a piece of resin demolded from a plastic or silicone mold. If so, my first thought is this blemish is from the last little bit of resin that wasn’t mixed very well. This happens when you don’t scrape the sides of your cup several times during mixing.

[Kathy]

Oh yes, surface problems. I’ve had these on many pieces, with different resins and it kept puzzling me. Just two days ago I talked with the owner of a resin company who has worked with different resins for 30 years. And he told me the same thing.
Well, first he asked me if I am using those very last drops in the cup, scrape and scrape or wait 40 seconds for the last drops to come out of the tilted cup. I said yes to all of the above. He explained to me that there lies the problem. In his experience you can never mix well enough to really get the resin on the bottom of the cup to be the same texture as the rest. So if you use this part on the surface (the last doming layer) you get something like looks like water stains. To avoid it he told me to leave a bit in the cup, or indeed pour your mixture in a second cup and stir again for a few seconds. Interesting that is topic comes up here now that I found an explanation after two years. I should have known Katherine would know the answer 😀

[Katherine Swift]

Aw shucks. You make it sound like I was clairvoyant or something. 😉 I found out the hard way too. Same thing happened to me when I was determined to use every last drop of resin.

[Rijacki Ledum]

One of the epoxy resins I’ve used suggests mixing for 2 mins in one cup and then pouring into a second cup to mix for another minute. I’ve used that advice with other epoxy resins as well since it is a way to make sure the bottom gets as mixed as the top. I also measure in 2 cups before pouring into one to make sure I have the right amounts for the ratio.

[Marie-Helene Grabman]

Can the spray that is used in your tutorial about clearing up cloudy projects eliminate the surface swirls? I am having problems with those too….they seem to appear after several weeks.

[Katherine Swift]

If the swirls aren’t deep, I think it would work. The spray doesn’t fill in gaps, but will give a shiny surface. If the swirls are deep, you are going to need another layer of resin.

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