Looking for alternative to gloss resin - Polyester resin

I love the way gloss resin polishes up and how it covers up exposed weave where the lap is sanded on the bottom.

But I have been having issues with getting it on thick and then it flows into concaves on the bottoms.

I haven’t actually done a cross section, but I have a feeling that by the time the resin levels out and sets up, it must be about .050" thick on the bottom of boards that have concaves.

Is there a way to reduce it so it brushes on thinner?

Or is there an alternative spray on finish that looks as good and conceals the weave where glass fibers are exposed?

The last board that I used gloss resin on the bottom actually had a puddle of resin at the bottom of the concave and it was labor intensive to sand it thin without touching the weave in the center if the board… Exactly the place where I don’t want to create a soft spot.

I have tried spray on urethane and a few other clear ‘paints’ and those are lacking in the quality of gloss resin. So what I would like to find is something that is the nice quality but without so much depth.

Xylene thinner + accel;erator + UV activated catalyst perhaps? Polyester resin

Any ideas?

Thanks in advance - !

Read my reply on your previous thread.  Don’t understand what you’re doing.  None of the things you mentioned belong together in a gloss coat.

What should I be doing differently to prevent gloss coat from flowing into the low spots of concaves, before it has a chance to set up?

I can’t imagine that pros have these issues. What do the pros do?

Xylene, Accelerator and UV Catalyst wouldn’t or shouldn’t be used in Gloss resin.  If you are going to thin Gloss you would use Styrene or Acetone…  it’s been my experience that Reichold Gloss resin thickens when not in use.  I thin it with Acetone.  I also add a cap full of Surface Agent.  I Catalyze it with MEK.  I shoot hot.  At least as hot as I would a Hot Coat.  I never have any problem with it provided I work fast.  Thinning will not avoid puddling in Channels and Concaves.  Your Brush Work is what prevents that.   I spread it fast.  It runs off the board fast and after it is spread if I do a good job, I will tip it off and that is it.  If I don’t do a good job of spreading, I will cross stroke and then tip off.  Most of the time I just spread it and lay it off.  When you are using gloss out of a pail everyday, it doesn’t have time to sit around and thicken.  So generally no need to thin.  Most Pros who do gloss everyday don’t thin.

Looking at your title;  the alternative would be Automotive Clear Coat.  Search the Archives for a thread by Resinhead.  He has that process down.

Im no expert, but I have spent some time with experts in various coating industries and from your description you are putting to much material on full stop.

Any coating is to be applied with an engineering mind set. Any product will have a manufactures specification of how thick a product should be applied for its properties to conform. That being said this is the surf industry. 

Any how, enough rambling. The gloss coat should be just thick enough to cover and adhere in a good fashion. Strangely, the gloss coat is not an area I struggle with. Sanding it is a different ball game! 

I think because we all strive for that perfect smooth finish it’s easy to be shy with that brush. Use the up and down, followed by the cross strokes to even spread and push away the excess. A final up and down with no pressure on the brush will leave it smooth



Hey - Sorry about that - I meant Styrene but I said Xylene

But that may be an example of the damage I’m doing to myself, by glassing in cold climate.

Truthfully, where I live, there is enough local market to support shaping/glassing industry on a small scale. But guys have tried and it didn’t go well because of climate.

Cold / humid conditions are the culprit. And successful board shapers /glassers have moved here and tried to set up shop with poor results.

Anyhow I’m making this sound even more complicated by over explaining.

I need to heat my glassing room better and let the resin and the board surface warm up to 70 deg or so.

I like leaving the ventilation on when I glass, but for glossing I’m just going to have to hustle and then clear out of there.

The last gloss coat I did, I warmed the resin, but then when I put it on a cool board, it became really viscous, and that was the issue, along with slow set up time.

So what I’m looking for is alternatives that work as well as glossing resin, but maybe have some reducer added for purposes of spraying… So I can get a reasonably thin gloss coat at about 55deg. 

I know that’s asking a lot.

But car painters add vehicle to their 2 part paint and mix it and shoot it… That’s the industry standard.

I’ll check into ‘Automotive Clear Coat’

It would be awesome to find something that fills micro scratches and cloth weave as well as poly gloss resin does

From what you have just told me;  forget about it.   If you are glossing in a room that is down in the 55 thru 60 degree temp, you will never  be able to do a decent gloss and polish.  You will have nothing but problems.  Slabbing, separation etc.  you will never be able to do it at those temps.  Exsposed weave and scratches are things that should be cured at the hot coat stage.  Curiosity;  Where are you located?

Northern CA - On the coast.

There’s a lot of surf here, but shapers up here usually send out shaped blanks to be glassed elsewhere. Even in the summer.

There have been guys here who shaped and glassed, but it would take 9 mo to a year to complete an order sometimes, because of the short window of opportunity for good glassing weather.

I was looking at automotive clear coat and it was around $80 for 1 qt or $160/ gallon.

I already have 3 qt of polyester glossing resin.

It would be awesome if I could reduce it with styrene and spray it…

… Add accelerator to set it off - Or even just brush it on reduced with styrene

Heating my shop to 60 deg is possible , but unless it’s a rare warm day, 70 isn’t do-able

So I just would like to find something that works @ 60

You can’t add accelerator to Poly Resin.  And you’ll  never be able to spray gloss resin.  Not saying it can’t be done.  Just saying if you try it;  You’ll regret it.    You have an easily solved problem.  Heat your work space up to 70 degrees and keep it there until your gloss coat kicks.  Simple remedy.  I live on the North Coast of Oregon.  I glass, hot coat and gloss in the equivalent of a car and a half garage with an electric 110 Cadet Heater.  No problema.  I wish the weather up here was similar to Southern Oregon or Humbolt, but it’s not.   Something that works at 60?   NOT!

Good enough - 

I warmed the resin up but not the rest of the room. That’s why it didn’t work

I’ll have to get some fresh filters for my respirator, cause I’ll have to leave the fan off to get it to warm up.

Coming from a guy who glasses in Oregon - you’ve got my attention.

BTW - I have some accelerator for poly resin…  Tried it once - Never wanted to use it again… I guess if I were glassing a shortboard on a cold day and there was a power failure.it might be handy.

Besides the Room Temperature.  UV Additive is a good way to go for lamination and hot coats.  In the 1990’s on the Central Coast of Calif. UV came into widespread use.  UV will set in lower temps.  We experimented with UV Gloss.  It just didn’t work out.  We all went back to MEK.  I think if I had more experience at the time I could have made it work.  But never got back around to trying.  The damned weather up here is so bad that it is difficult to do any UV without a “Box”.  I do lams and hot coats with UV from May thru Sept.  just haven’t ever got around to building a box.  Would cost me about $500.  If you watched me thin and prep Reichold Gloss for a Gloss Coat you would shake your head in amazement.  I don’t reveal the details on a public forum because I would get ridiculed by the know it alls on this site.  But it works for me and I don’t care how anyone else does it.  PS  I am overly generous with my MEK.  Especially when using Pigment.  Two or even three times the Norm.  I have learned to work really fast.  Look it over carefully and then stop before it sets.  That way I am never mid brush stroke as a hot coat or gloss starts setting.  That’s where the problems start.  

There is a clear gloss gel coat made to be sprayed as a first coat  on the mold ,then spaying the color coat.  Might work as a top coat. I personally have never used it on Surfboards. You will still run into the same temperature range 60 to 85 degrees.  The spray equipment will have to have a wide tip.  It is catylized so be very careful with timing. . Might look into some clear Awlgrip Marine coating very expensive but once it drys it is a rock hard finish with some stretch. No need sand and polish after it is done.


There is a clear gloss gel coat made to be sprayed as a first coat  on the mold ,then spaying the color coat.  Might work as a top coat. I personally have never used it on Surfboards. You will still run into the same temperature range 60 to 85 degrees.  The spray equipment will have to have a wide tip.  It is catylized so be very careful with timing. . Might look into some clear Awlgrip Marine coating very expensive but once it drys it is a rock hard finish with some stretch. No need sand and polish after it is done.


I’m not sure you want a thinner resin. A more viscous resin may stay in place better. Your issue (as per Billycvs’s reply) is probably more the amount of resin.

Here is a trick a lot of people will enjoy, taught to me by Halcyon, if it’s not already in the technique bag: take a cheapo plastic squeegee (the yellow kind, whichever type), and cut a line of half-diamonds into the blade. What I mean: imagine a square about 2mm x 2mm, then look at it as a diamond instead, and bisect it longitudinally. A line of 15-20 of those along the squeegee blade allows you to squeegee out your hotcoat when you lay it down, leaving raised lines of higher areas of resin across the swath of the gaps in the squeegee blade. From here you can just proceed further as normally, or as amended to adapt your brush technique to this new 1st step. You’ll get a more even coat from the start, as well as getting a thinner one with more evenness if that’s what you want. For a thicker hotcoat you would just cut bigger half diamonds.

Just do like Yater did in the 60’s.  Squeege the whole hot coat.  If the hot coat is your problem (covering weave and scratches) apply a second so called “piss coat.”  Which is nothing more than an Acetone thinned hot coat with a little extra Surface Agent.  Lay it on as nice as you can and then hand sand.  Then go onto gloss.  I have said it before;  Your Gloss is only as good as your hot coat.  How it is put on and how well it is sanded.  The purpose of the gloss isn’t to hide burn thrus and scratches.  By the time you have sanded the hot coat, there shouldn’t be any exsposed weave or scratches.  Have you had problems with your hot coats?  Because at 60 degrees, I would think you probably have.  Should be your goal to get it done using the same common industry technique.  No need to reinvent the wheel. Just get that room warmed up.  I’ve never heard of anyone warming Poly resin.  It’s pretty Flammable you know.  I have Microwaved Part A Epoxy.  That works really well.  I turn my little 110 Cadet heater own the night before.  The next day my room is warm and my resin is room temp.

from boat supplier you can find tixotropic iso poly top coat. They are formulated to not run when they are painted on vertical surfaces. i always start sanding bottom of my channels by hand then i move to sander. 

Thanks for the good advice, Guys.

I obviously need to warm my room up better. I’d warm up tha air with a heater and heat the resin with a heat gun but then it would get viscous when I was brushing it on. I thought it was gelling, but the stuff in the bottom of the cup wasn’t gelling yet.

 Now it all makes sense.

I’ll also try some of these new techniques.

I almost always put extra wraps of cloth around the tail and sometimes the back part of the rails if I feel like I need something there to sculpt some hard edges. So there’s always some weave that needs to be covered. But Somehow it turns out right in those areas… It was just that the cold resin was settling into the concaves.

Try using your tape as a resin dam on the Hot Coat.  Streamlines the process and makes an easy hard edge.  Putting extra cloth around the tail adds time and creats problemas.

The squeege modification you describe sounds a lot like a wax comb - I’ll keep it in mind for my next hotcoat