First off, Thanks to everyone for there help in my first board building experiment.
My question is when I put on a epoxy gloss coat (I realize it’s not gloss resin but I wanted to put another layer on top of the hot coat to shine the best I could) it separates in small areas similar to the way water does on a flat glass surface leaving areas that have no resin. I have found this make sanding hard as my sander won’t reach down into these small areas without removing alot of gloss resin (I’ve even sanded some of my pinlines off trying to get these areas flat). Please note that when I brush it on it looks ok then after a few minutes it separates. Could it be that I not putting enough resin on? I’ve used 6oz of resin/hardner per side of an 8’ board.
Also, could a lot of my sanding problems be related to the fact that I use a dewalt orbital sander (typical woodworking type)?
Thanks very much and looking forward to trying to ride this thing next week.
Fisheyes are either the result of impurities on the lam (oils from hands, dust, etc.) OR the result of higher humidity. I have found that most of my fisheye problems in the past were the result of trying to hotcoat with epoxy under humid summer conditions.
This question is timely for me. I’mm looking at doing the same thing to the Moon Rocket.
It’s getting christened this weekend and I keep looking at the gloss on the hull and thinking “I can make that look smoother”, like a dermabrasion for a pimply faced kid.
I’ll be following this thread intently as I’m sanding it tonight. Epoxy (again) tomorrow morning.
Try an oz. per foot of resin. Watch the finger prints they cause seperations. I handle the boards after sanding with gloves. Double Additive F. That helps with flow. Heating the resin a bit, if it’s cold, will also help.
Well…I just got fisheyes on two different days with temps in the 70s, 10-25% humidity, sanded dna clean deck (both times) wearing gloves, etc. both times using fast resin hardener…when I went with the slow, it was nice and smooth, the way it should be (all were with additive F)…After several experiences where the fast hardener kicked so fast that it started smoking in 5 minutes and now the fisheyes, I’m done with it…
Another thing to think about is the sandpaper you may be using. If it is stearated, it has a coating on it that keeps the sandpaper from clogging up as easily, but can leave some of the coating behind on the board, causing separations. It happened to me using a great Norton premium sandpaper, so now I just use regular, non-stearated paper. I really liked the Norton stuff too, it was flexible (wouldn’t crease), and would last a long time…oh well.
If you want more time to brush, lose the X-55. Otherwise, that’s the way I have gotten my best coats so far. Also, another way to rid the board of grease and oils is to wash it with Dawn dishwashing detergent, and towel dry (so no waterspots), and when you bring it back inside, wipe with dna and a lint-free rag (or as lint free as you can get), to get the towel lint off. My best coats have been laid down after I did this, and now I do it every time for gloss.
If you have acrylic pinlines, though, DO NOT use dna, Dawn and then shop vac (or something) for the lint would be the best choice. The dishwashing detergent won’t destroy acrylic paints, at least not yet for me. I found out the hard way what dna does to acrylic paints, and later to india ink. I have several boards with multiple gloss coats, so don’t feel alone. Once you get the ins and outs of RR epoxy figured out, it is a dream to use.
Good advice in this thread. Epoxy in general is a little more tricky. But if you follow these guys advice you’ll get it down. You just have to be careful and not cut corners to save time.
Hicksy, do you call that moon rocket a double stinger, or mega wings?
First off, Thanks to everyone for there help in my first board building experiment.
My question is when I put on a epoxy gloss coat (I realize it’s not gloss resin but I wanted to put another layer on top of the hot coat to shine the best I could) it separates in small areas similar to the way water does on a flat glass surface leaving areas that have no resin. I have found this make sanding hard as my sander won’t reach down into these small areas without removing alot of gloss resin (I’ve even sanded some of my pinlines off trying to get these areas flat). Please note that when I brush it on it looks ok then after a few minutes it separates. Could it be that I not putting enough resin on? I’ve used 6oz of resin/hardner per side of an 8’ board.
Also, could a lot of my sanding problems be related to the fact that I use a dewalt orbital sander (typical woodworking type)?
Thanks very much and looking forward to trying to ride this thing next week.
Bill
The resin has a high surface tension so it will only require a minuscule imputiry to start separating. Heating and thinning the resin will help a bit. RR uses a xyleen based additive which a lot of swayfolk have used sucessfully, but you could try minute amounts (just a few drops!!) of a thinning agent (xyleen, tolueen, paint thinner) but these are wildly toxic and dangerous to have and use, I wouldn’t use them unless I had a “professional” protected working environment.
You should wash the board with alcohol to de-grease it this helps, keep the room dust free.
You could put a thick coat over a thick coat (time consuming repeated process of brushing on resin…), sand fine grit, more resin, fine grit and then some finer grit (water sanding to avoid melting the resin!!!) and then polish like you would a poly gloss. You’ll get a “decent” shine but never as nice as a poly gloss. At least, I’ve never seen epoxy shine like that in person.
If your board was 8’ long 6 oz was not quite enough resin. A rule of thumb from Greg L is a little more than an oz per foot when hot coating or glossing. Search the archives. There’s a post by Greg L with info on suggested resin amounts and lots of other good info on RR epoxy and eps boards. Contaminated spots (from fingerprints etc) can cause this problem but you need enough resin to flow or you will get separations. Next time if the resin has already hardened try lightly sanding or scuffing the bad spots with a scotchbrite or sandpaper and fill with small amounts of resin before sanding the whole board. You can also paint extra resin over these spots before your hotcoat or gloss has fully hardened. If you do this soon enough the resin will still make a chemical bond. You have nothing to lose at that point anyway.
One rule of thumb: If you’ve done everything you can think of so you won’t get separations and fisheyes, watch for them anyway as the resin sets up. If they appear, use a stick dipped into a small cup of resin to drop some resin into the crater. Let it overfill a little. It’s easy to sand off a small bump later. Doug
I would say that contamination is probably the main culprit. I have glassed 2 boards with RR epoxy. They were done outside in the backyard here in New Orleans in the Summer. For those who don’t know, temperature ranges from 85-95 F and humidity can be around 70-100% even on a sunny day. Glossing turned out great. I’ve had fisheyes when my greasy paws touched the blank. Also, I now wear a headband of some sort to prevent sweat from dripping off my forehead, neck, or face onto the board. Scrub with denatured alcohol and then scrub again, that’s my advice. Keep it nice and clean.
I’m sure a lot of people will think I’m nuts, but I just don’t like the way denatured cleans a board. Throw on some gloves and hit it with some acetone. Not only will it be clean, but your tape will stick much better too.
But no acetone with epoxy, it inhibits the reaction.
I use plain water and just dry well. Only had the separation issue once, a long time ago, and it was cold & damp in my shop & before I was regularly warming the resin. Plain water. Dry well. Don’t overcomplicate this stuff…
