How much catalyst for for pigmented UV resin

Hi all,

I’m just after some advice if anyone can help.

I am making my first resin pigmented board (Black lam coat) and I have realised that I have mixed all my resin up with UV catalyst … obviously this may not then kick the through such a dark pigment.

In what ratio would you suggest adding catalyst to (a) ensure the resin kicks all the way through the coat and (b) not completely kill the one benefit for me of longer working time (being the backyard hack hobbyist :slight_smile:

If I added the catalyst at say 50% of the standard ratio’s does it eventually kick all the way through?

Thanks in advance guys … can easily elect not to add the pigment but the 16 y.o has designed up a pretty nice looking little licorice stick mini simmons and I must admit, if it comes off as he has suggested then it wil;l look pretty sick.






Don’t forget, all that pigment will retard the mixture.

There is no set measurement as all the factors change from quanity to temp.

maybe 10-15 CC for about 15-20 Min. of work time.

If it’s cold, longer.

If hot maybe less.

Work fast.

If you finish too early, the UV cure will kick the surface resin.

Black boards are the coolest.

I do lots.

Use a black Hot-coat for a deep black.

Have fun.

Straight UV with black pigment might not ever kick.  The amount of catalyst you add to get it to kick is a crap shoot.

Thanks guys. Much appreciated.

Barry - just love that Black with White stripes. We have a football team down here called Collingwood who wear the black and white stripes … I’m kind of obligated to hate Collingwood with a passion but could put aside my predjudices for a moment (my team wear Brown and Gold so I can’t really make a Hawthorn board). 

I’d love to understand the process involved in that color layup.

After reading a bunch of stuff over the last little while was tending towards a black foam tint and then just laminate clear - if i could get a black hot coat over that area neatly i can see how it would pop but not sure how you then get the clear hotcoat on the rest - obviously doing at the same time would be tricky. Would this work …?

  1. Black foam tint. 

  2. Clear lam

3. hot coat the black section with pigment (careful on the border) - let it kick

  1. sand back margin lightly - clear hotcoat over rest of the board into the margin.





hey chris 

Staining the foam is a good idea, I wouldnt recommend putting black pigment over the clear weave though, Ive done it before and thought it looked kinda shabby. 

In the  past I have done very deep, dark tints by painting the blank and then tinting the lamination.  Gives it alot of depth.  And;   Don’t get me wrong: You can definitly do a black tint or opaque, but you have to catalyze it.  And how much MEK P to use is a bit of a guesstimation.  Cobalt might be a good idea as well.  You can also do a black opaque or tint and then paint the stripes on the sanded hot coat.  And finish with  gloss and polish or clear spray  finish.  Be careful in the sanding/wet-n-dry process that you do not sand into your painted stripes.

What would you use to stain the foam?  Rattle can spray paint from an autoshop?

mojo rizing you can use tinted resin, to stain the foam. Pull it off with a squegee. Heres one I did last month 

I would go with the black lam. It will look much nicer than a foam stain or painted blank.

If you kick it at 5cc-7cc you will have plenty of working time ( 30 mins or longer). Just let it sit over night before you stick it in the sun to flash it if your worried about it.

I have done a few black boards. Its no different than any other color except when your done and surfing its a constant struggle to keep wax on the thing anytime the suns out haha.

.02 from a backyarder- I wouldn’t sweat the UV resin curing unless you plan on leaving puddles of resin in your lam, but definitely use some cat… and squeegee that bugga good. For this black bottom lam below, it’s a 5’8 x 18-1/2,  I usually would have used about 22 oz of UV resin, probably close to an ounce of black pigment and after mixing that up good, squeezed off about 10-12 drops of cat. Didn’t bother straining opaque black. Usually 80-85 degrees in my shed, it got gooey in about 15 minutes or so. Plenty time for a cut lap lamination. Trimmed the lap then finished it off with a couple minutes in the blazing Hawaiian Sun


Thanks so much guys for the feedback. I’ve got some options by the look of it, Will mash up all these thoughts and just crack in, after all it’s a board - not brain surgery. Experimentation and challenging yourself is all part of it.

Bud - that board looks sweet. 

Cheers all and a Merry Christmas. May there be a good swell delivered from Santa under your tree.