Epoxy resin tint questions

Hey,

just finished laminating, hot coating, and glassing on the fin of board number five. This is the third epoxy board. I use resin research epoxy, and on the last one I didn’t use any additive F (because I don’t know what it does). I mixed in blue and tinted the resin, and stirred the shit out of it. After pooring it on and doing the whole lamination, I saw that there were streaks in the color. It can’t be because I’m not stirring the resin enough, because I couldn’t stirr it anymore. My friend swears it’s because i’m tinting with epoxy resin, because we did a tint and swirrled up a whole board with polyurethane resin and there were no problems or heavy/light spots, but for some reason when I tint with epoxy I can’t get a consistent solid tint.

What am I doing wrong?

thanks

Not using Additive F shouldn’t be your problem. I’ve done lots of tints and swirls with epoxy, but the only true tints I’ve done have been epoxy over PU and they have come out pretty even. Were you using EPS foam? EPS ends up with a lot of holes after shaping that will fill with resin and show up darker than the rest of the board.

Otherwise it could be color. Blue is a tough one to do properly. Yellow is the easiest and will look halfway decent on EPS. Light spots could be air bubbles. Squeegee pressure and pass lines could affect things too.

Your trying to do things with epoxy that are really hard. Epoxy & color not for the faint hearted.

You’ll see most custom epoxy hand shapes are all done clear. And if there is some color, it’s usually painted after the board its made…there is a reason for that. Epoxy can’t be forced into the cloth like poly, it has to soak into the cloth. So it makes it even that much harder to get an even color look. And then if you over work it, it gets all milky and blushed. It makes a great board, and it makes a great looking board…as long as it’s white.

Hi poser516 -

I’ve been there.

There are some new pigments available through Fiberglass Supply that are “specially formulated” for epoxy. I have not tried them myself.

Some of the other standard pigments have tiny flecks that apparently don’t dissolve readily in epoxy. I’ve run pigmented epoxy through all kinds of filters and still get some flecks that are invisible to the naked eye and once they hit the cloth, they smear.

My last pigmented epoxy resin was run twice through fine mesh filter cones like what they use at the hospital to look for kidney stones in urine. The mesh is so fine, I have to microwave the epoxy to thin it out or it just sits and plugs up the filters. I still had a couple of minor smears.

Like yours, the pigment (blue) seems to work fine with polyester resin.

A possible solution is to mix small batches of the pigment with acetone and run those batches through the fine mesh filters before mixing with resin.

Kidney stone filters?

Paging Gregg - Mr. Loehr’s pigmented epoxy boards are perfect in color everytime. Check out the stack of light blue boards in the background of his glassing video. Show us the way - please???

Thanks for the help everyone. It’s greatly appreciated, as always. Rachel, I used a walker blank. I have only used an eps blank once, and it was a serious pain in the ass, both shaping it and glassing it. John, filtering out the resin first seems like a good idea. I may have to try that next time. Man, everytime I glass with epoxy I have a little issue, and I need to figure it out next time around. Its just more complex then polyurethane resin, and there are a lot more issues that can be had. It’s just so much stronger. And I like how it’s odorless. So far, I still think it’s worth it, because I have yet to get a ding from losing my board to the rocks because the stuff is so strong, but i want my boards to look good.

greg, check in please.

i’d be willing to bet that squeegee pressure is the culprit. as you do your final pass across a freshly-tinted lam, whatever excess resin you pull off runs out from the middle and off the sides of the squeegee. this leaves a line of tinted resin, which is partially re-absorbed back into the cloth. also, you’re probably using firmer pressure at the center of the squeegee than out at the sides. these things together can result in the streaks that you’re seeing.

good tints are doable with epoxy…just gotta find that magic touch.

Hi Jay -

These. A bit finer than standard paint filters.

Hey guys so im trying to figure out a better way to glass my pu decks.

At the moment im glassing the bottoms unsealed same as pu, but when I glass the decks the stringers where reacting to the epoxy and blowing out. I’ve fixed the problem by sealing the stringers first but when doing colour tints the seal has to be spead over the whole deck and done very clean to prevent the tint from being uneven. I was wondering if there was another way to glass the decks without having to do a seal coat ??

My ideas are i could tape off the stringer and paint on with clear.

Or maybe pin pricking the bottom could allow the air from the stringer to escape from the bottom ??

 

add the pigment or tint to the hardner first then combine with the resin part.I have done a lot of cut lap pigment and tint boards in polyester…have found that eps epoxy is not the best for tints, pigments, laps never zipper cut that clean . bleed a little ,kinda streaky maybe due to  fairly open cell eps   used here…can sand the laps down to tape but thats an ichy little exercise.

I’ve done quite a few and gotten great results, but there no shortcuts, quality takes time, I double sealer coated with a mix of RR and baking soda, hand block sanded the first coat, #220 on my DA sander second coat. Dropped on 3 layers of the green tape right on top of each other for the lap, you cannot cut lap safely or score the foam or get out gassing, after cure I used my variable speed sander on top of the taped area, lifted out the masked portion, leaving a perfect lap, repeated same on bottom.

I added color to ther resin portion, strained it through double strainers, added part B, strained again, not hidden disasters


Zack,

See this in every Epoxy glass shop I’ve been to.

First off, it’s not easy to poperly glue up an EPS blank. Rough cut, and voids galore.

Second thing is EPS is loaded with gasses and air. It’s not solid foam. When it heats up, EPS gasses only release one direction, up.

When the temp. is dropping, the opposite is true. It actually sucks it in. Both air and resin.

A lot of production glassers laminate thier decks in the mornings.

That’s when the temp is rising.

Try doing the decks in the afernoon.

You can, as the decks begin to gas, take a small sewing needle and push the fibreglass weave apart to let gas escape and cloth to lay flat.

I know the pain of coming back to the board and find a huge volcano of fibreglass sticking up.

It works. A friend of mine, Pedro taught me that 25 years ago. He was at the forfront of Epoxy technology. He had his own Epoxy resin long before other brands.

Zack, you can also heat the blank first, then lam the deck as it cools.

Fortunately for me, I have a heat box I use to dry my airbrushes and such.

it comes in handy for other applications as well.

Good luck mate.

Cheers.

cheers for the info guys

I did a small expirement on the weekend. Using my idea of taping of the stringer for (polyurethane foam) and it worked quite good. I had no gassing from the stringer and the foam was left unsealed to stop the tint being affected from the clear seal.

Yeah barry I learnt pretty quick the nature of the gasey eps. Quite a trip when coming from poly. I started making small pin pricks on the nose and tail to allow the air to vent and havent had a blow out since ive done this. I then just fill the small pricks with some thick cab mix to prevent pin-holing, before I hotcoat.

The room we glass in is also heat controlled to 28 degrees and never gets turned off even when we leave. So were always glassing in optimal temps for the boards to gel fast. Usually my first board will start gelling by the time I start my third board.

Just juice we add tint to the hardner so we can replicate colours across multiple boards. We will do the bottoms at 100%, then drop the percentage to 80% colour 20%clear (4oz) 60% colour 40% clear (6oz) for the deck to replicate the colour on the bottom.  I always grind my tape off like jim says but I use a small die grinder rather than a big sander, find i can get more control. I also only use one layer of tape so I have to be careful not to sand through into the foam.

This was a batch I worked on over the weekend

 

Nice punchy grey tint Zack… even in polyester it can be a little tricky,

in an effort ot avoid out gassing, if the board gets a deck plug ( I avoid leash plugs, it is straight through route and can wick water around it ) and or fin boxes, puncture a small hole where they will go as a passageway to vent off

Golden nuggets, guys.

All the best

 

Just did a green epoxy tint over EPS for the first and last time.  The spackle seems to absorb the tint and forms specks of darker color in the foam.  Kind of a pain and I won’t do that again.  However, epoxy tint over PU, that has been nicely finished, is good.