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View Full Version : epoxy color for plywood tanks


karimwassef
09/21/2017, 07:48 PM
I've used epoxy for plywood tanks, but always clear.

Since I'm planning on much larger builds, I'm consider pigments for the first time.

http://www.uscomposites.com/epoxy.html

http://www.uscomposites.com/pigments.html

anyone have experience/learnings specific to epoxy pigments? Thinking Keel Blue outside and White inside. :D

mcgyvr
09/22/2017, 05:38 AM
personal preference.. Want me to tell you what color car to buy too :p

karimwassef
09/22/2017, 08:18 AM
No. No. I guess I should be clearer.

I'm looking for things to watch out for.
- does it make the epoxy weaker?
- does it take longer to cure?
- does it add bubbles to the mix so use a slower mixing technique?
- does it make it harder to see bubbles so use a heat gun more often?
- does it change the surface finish so make sure to sand a little more between layers?
- would it be better to go clear-color-clear-color to allow defects to show better?
- would it be best to go all clear and only use color on the top most coat?
- would it be best to put one color coat in the middle and go clear everywhere else?
- does it mix unevenly in a large batch so go even smaller than usual?
- is the pigment more moisture susceptible so keep it sealed very tightly?
- are there any pigments that have better or worse properties on the finished epoxy?
- do I need to surface treat the wood differently?
- I don't use fiberglass. Does using a pigment change anything that could cause me to reconsider?

... I'm not paranoid :D
I just plan for the worst and expect the best. And ask to learn from my friends' failures when possible :lmao:

mcgyvr
09/22/2017, 09:08 AM
Ok.. gotcha..
Simply call them and ask your questions...
They will give you a better answer than anyone here and thats their job...


As to you not being paranoid.. I'd get a second opinion on that one too.. :p

der_wille_zur_macht
09/22/2017, 09:33 AM
I've used their products on lots of projects for probably 20 years, since before I even knew people made tanks out of wood. Many of those projects, including tanks, used their pigments. It's easy and there are no effects. You just add the pigment and mix as usual. End product is the same as far as I've been able to tell and there are no handling differences.

My 360g was white on the inside. I liked it, but it comes with the obvious caveat that it gets dirty looking very easily and you need to either live with it or spend time cleaning. Once the coralline takes over it looks OK but prior to that, even just a day or two of film growth makes it look off color. I had my eurobrace above the vertical walls to create some shading, which definitely helped.

karimwassef
09/22/2017, 09:54 AM
Thanks!

If you were to do it again, would you go pink or light blue instead?

krazyk148
09/22/2017, 01:30 PM
MAX ACR Black pigment is extremely black haha It definitely isnt clear at all with full coverage

karimwassef
09/22/2017, 01:59 PM
I'm going with US composites :) they're naturally ~clear

der_wille_zur_macht
09/22/2017, 02:25 PM
Honestly, I think any non-black color will look weird once it has film algae growing on it. I might try light blue or an aqua color if I was doing it again. I would probably try to mix something to get a match to that sort of bright blue background color present on natural reefs.

karimwassef
09/22/2017, 02:44 PM
http://www.uscomposites.com/pigments.html

Check out the colors on their site. I'm liking Keel Blue

http://www.uscomposites.com/Images/pgmts/full1.jpg

But was considering mixing red and blue for purple or red and white for pink. There's opaque and transparent colors.

Since I'm expecting at least 4-6 coats, does it make sense to go clear and only color the surface?

der_wille_zur_macht
09/22/2017, 03:03 PM
I poured clear first and then only tinted the top two coats.

karimwassef
09/22/2017, 03:20 PM
Thinking the same. I'm sensitive to bubbles, so I added vibration and a heat gun. Clear is very easy to work with. I can even use a spotlight at an angle to check.

I can't do vibration at this scale... maybe I can sidemount a small compressor?

But I think I'll need to be more vigilant with the heat gun.

Gorgok
09/22/2017, 08:11 PM
Mold making sometimes use compressed air blown on the surface to pop bubbles. I would imagine thats what is helping with the heat gun more than the heat (which might help but also probably dry it faster...).

karimwassef
09/22/2017, 09:01 PM
bubble removal

acetone misting method:
<iframe width="560" height="315" src="https://www.youtube.com/embed/2PKn-59pHNM" frameborder="0" allowfullscreen></iframe>

heat gun method:
<iframe width="560" height="315" src="https://www.youtube.com/embed/yragutQn-fM" frameborder="0" allowfullscreen></iframe>

heat/warm bath method (not practical IMO):
<iframe width="560" height="315" src="https://www.youtube.com/embed/oUXDoeGAdIs" frameborder="0" allowfullscreen></iframe>

vacuum degassing method (not practical IMO):
<iframe width="560" height="315" src="https://www.youtube.com/embed/dos38dCV-rs" frameborder="0" allowfullscreen></iframe>

ultrasonic degassing method (not practical IMO):
<iframe width="560" height="315" src="https://www.youtube.com/embed/23nsW2yAl_o" frameborder="0" allowfullscreen></iframe>

toothpick method (not practical IMO):
-no video found-

salty joe
09/23/2017, 06:32 AM
I found no differences in adding pigment except for a little longer curing time. I mixed dark blue with black for super dark blue for the last coat-I like it.

Lotsa ways to pop bubbles. I just got a propane torch on medium/ low and quickly ran over the surface. A 4'x8' panel only took a few minutes to clear the bubbles.

karimwassef
09/23/2017, 09:27 AM
I like the acetone spray.

My areas are massive.. 8'x13'x2', 8'x12'x27", ....

And since the sump sits on the bare concrete, I need to put a couple coats on the floor face too.