Today I’m doing a large repair on one of my boards. I’m ready for the gloss resin. Since I haven’t worked with gloss before and it’s pretty hot today( about 85 F), I decided to do a one ounce batch to check the working time. I put in 10 drops and 45 minutes later it still wasn’t set. I figured gloss might be slower but this is too slow so I batched another ounce with 15 drops. Right now time elapsed is 1:20 on the 10 drop batch and 0:35 on the 15 drop batch. Neither has gelled.
Is this typical for gloss or do I have a problem?
The catalyst is about 4 weeks old and the resin is only about 2 weeks old. I’ve used the same catalyst on my lamination and sanding resins and it worked fine. I bought the gloss resin from Krystal Liner in Costa Mesa which is a reputable shop for glassing supplies.
I suspect I have bad resin. It’s pink in color and after a few minutes with the catalyst it turns toward orange.
I’m glad I tried the trial batch. I don’t have any on the board yet.
Gloss kicks differently than other resins and the transformation from liquid to gel is a lot longer, although the transition time from gel to semi-hard is about the same as sand resin. I use 1-1.25% catalyst and have waited up to 45 mins to gel depending on temp (60-70 F). Don’t be tempted to use more catalyst because the finished coat will be very prone to impact shatters later. I panicked the first time I used gloss from a can expecting a 10 min. gel time. After 20 mins I lost it and wiped everything off with about a quart of acetone. Since then I’ve learned to use the longer kick time to deal with air bubbles, brush hairs, dry spots, etc.
Howzit Ryan, A properly mixed batch of glossing resin should kick in 10 to 15 mins. I thin mine with styrene and S.A. which slows the kick time but it still kicks in 10 to 15 mins. You said your test batch turned orange after catalyzing, it should turn more to a brown color. Do you have a thermometer and a hygrometer in your shop, the hygrometer measures humidity which can affect glossing resin. Aloha, Kokua
I contacted the supplier of the resin. After talking to them they decided to make a test batch with the gloss they had on their shelf. It turns out that the resin is slower setting than it’s suppose to be. I just take it back for a refund. I guess you can never be too confident that what you’re buying will do what it’s supposed to. I’m glad I did the trial batch and none of it wound up on the board. That would’ve been a mess. I think I’ll try a small batch every time I get new resin.
hey I realize this is probably a bit late but the exact thing just happened to me today, only on the board. After an hour even the left overs in the bucket hadn’t started to gel. I left and went to work and checked it once I got home and it seems as if it has set up fine just in super slow motion. anyway hope that helps.
Kokua, do you mix your own gloss from lam resin, or just add the styrene to the ready-made stuff to get a 15 min kick time? I buy my gloss from the same place that Ryan did and also at other suppliers. I’ve never bothered to look at the drum labels, but it’s always the same light amber color and takes 30-45 mins to gel at about 1%. Over the years, I just assumed that pre-made gloss behaves this way. I’ve never had any long-term problems with full boards nor repairs from my ding biz. Since Simon added that his gloss also does this, please let us know if you think that this may cause problems. Thanks
I kind of wish I hadn’t mentioned where I got the resin. They were very cool about the problem when I talked to them about it. I will still buy from them. No matter who I buy from I will do a little test batch just to be sure. I’m a total newbie when it comes to this stuff so I tend to do test batches even if there is a big weather change. I’m just not that confident in what I’m doing. Besides, you never know when you’ll get a bad batch.
Simon, I wonder if you’re in Southern Cal and if you got some of the same material? I bought mine about 2 weeks ago. When I called the shop they said they still have the same batch because they don’t sell much of that type of resin. I suppose that’s because most amateurs, as I am, just stop at the hot coat and the pro’s buy other resins and modify it to their needs, like the other guys posting here.
On a slightly different topic, I understand as a rule of thumb that the faster you make the resin kick more brittle the final material will be. Is that true?
It’s not so much how fast a resin cures as it is what is making it cure so quickly.
When you add the MEKP you are initiating a chemical reaction that I do not have enough knowledge to explain with any pofficiency, but what happens is that in order for the resin to cure it needs to become non-elastic…this is the job of the catalyst, MEKP. In order to for the resin to become non-elastic (cured) the catalyst litereally transforms the resin from flexible (non-cured) to non-flexible (fully cured).
So the end result is that you ahve a material that has structural strength but is more prone to snapping and cracking due to it’s lack of flexibility. Spider cracks, raail cracks, the cracks that run along the the entire width of the deck, those are all atributed to brittle resin.
The moral of the story is this, the larger the ratio of MEKP in your resin, the less flexible the final outcome cures at.
Never fear a slow cure. time is on your side my freind!
Howzit Pete, No lam resin in my mix, just 10% styrene and 5% SA, 1 1/2% cat. Another thing, sounds like you may have bought Silmar glossing resin which takes longer to kick. I buy Reichold glossing resin, it kicks faster than Silmar. Some builders don’t like to thin their gloss resin this much because it makes for a thinner gloss coat which is easier to burn thru and hit weave when rubbing out. What I’ve found is this mix smoothes out so well that you can start with 400 grit (I use 320 lightly first on the bottom to get it flat) on the deck. Less sanding so you don’t burn thru. I know there’s a lot on this subject in the archives, so check it out. Aloha, Kokua
Like Kokua said… you probably have Silmar Resin.Silmar has a very light tan color whereas Reichold tends to be red to purple in color.With Reichold I use Kokuas mix…with Silmar I use it right out of the can(its thinner than Reichold).The clarity of Silmar is why it takes so long to gel,The promoters in Reichold give it the purple color but it gels super fast.Silmar is a great product and is fine for boards with color on the foam.If you are doing color on the hotcoat I would go with Reichold because it kicks fast.If the resin takes 30 minutes or more to gel it may cause pinlines to bleed.I’m not promoting one or the other.It’s like a tool…use the right tool for the job.
Kokua thanks for sharing your knowledge with us. I checked with my two main suppliers and it is indeed Silmar resin. Like you, I use gloss so that I can start sanding with 320. Much of the work I do is repairs to flat areas which always results in a square tape line border after hot coating. Blending that border cuts into the old glass, so the grit must be as fine as possible and still cut without excessive heating. So I use 220 to cut the tape line, gloss coat a slightly larger area, and then start with 320. The gloss covers the 220 scratches and the 320 blends in the edges without too much sanding of the old glass. Many of the repairs I do are high-end longboards which are fully painted between the hot and gloss coats. Using anything less than 220 (even by hand) will tear thru the gloss and wreck the paint. I also use gloss on shortboard repairs and just leave the 400 finish.
Howzit Pete,Wow this is a post from way back and have found a solution for slow kicking gloss resin that is either Silmar or just old.Add some Lam resin to the batch and it makes a big difference when it omes to he kicking off speed. I would say 5 to 10 % ought to do the trick and watch the difference, amazing . Aloha,Kokua
Silmar had come up with a waxed finish resin in the 80’s that was being promoted as a “glossing” resin, I hated it, brush lines didn’t flow out like Reichhold, was softer and did not polish out well.
I see shops cut gloss with Silmar, it speeds up gel time, but why F with a good thing
Im no chemist, so I dont do much manipulating with my gloss coats…
but,
I use the stuff foam ez sells I think it the reichold brand and I do add a splash of SA to it and mix it in good then 1.5% mekp mix again and shoot it as thin as I can push it.
I like shooting gloss between 75 and 80 deg F, thats were I get the best results,
I have had times where it took the gloss over an hour to gell, still came out good, just scared me ,thinking I forgot the cat,
Old school adds a drop or two of cobalt and or DMA (dimethyl allylate), if temps are below 40. I have glossed at 27 degrees without many problems starting at 2 percent cat at 70 degrees and adding more cat as the temp decreases- roughly a percent for every 10 degrees down. Also great for real resin pin lines. See if they still have cobalt at Christaliner. Gloss resins are inherently more brittle because of the addition of acrylic monomers that increase optical clarity.
Gloss resin is britle because of the increased barcol hardness, this is why it polishes out so well and why epoxy is so much harder to polish, extreme elasticity
JP your one of the best craftsmen- worker I know, and pretty sharp, but doesn’t barcol hardness have something to do with a test and a sharp penetrating object? I am not a chemist, but there are other additives in gloss resin that increase its barcol hardness. A little Acrylic monomer really makes it shine; nonetheless, acrylics are inherently brittle. What I have noticed is how tangential this place is, yet still some good information here from experts like you.
Seems like whenever one adds something here, someone comes around to shout him down- kind of like this industry.
Barcol hardness isn’t the test for penetration resistance, but a materials hardness , like lacquer, one of the hardest man made finishes there is, much tougher than gloss resin
I just looked up test for barcol hardness, it does list it as a test for resistance to penatration, I do stand corrected Ghettorat, but tool steels are rated as to their barcol hardness too ? I ain’t really a genius