Hello all, I have brush strokes showing in the finish coat. I though I brushed it on nice and thick, didn’t set it off too fast, but after initial rubout it shows even some cross strokes. The finish coat was lam resin with surfacing agent and cured nice and hard.
Obviously, first I need a softer brush, and maybe to leave more resin on the board(?) Next, I have to wet sand more/better. But I’ve never used wet/dry with a power pad, so has anyone got useful suggestions? I’ll be using a variable speed sander, so speed control should be good. Somewhere here I read to not use water for this, but to do it dry. I wonder if 400 grit dry will clog, since there’s no water vehicle to carry off the dust.
Let’s hear, who has done it and what’s the proper procedure for finish coatwet/dry sanding?
Viscosity is a big factor with brush strokes. I use straight gloss resin mixed with more sytrene, SA, and 1-1/2% catalyst. This is a very thin mix, which levels nicely. You can also minimize brush strokes by using a thick 4" brush and a lighter touch on the final passes.
On the sanding, I sand up to 400 dry and blow off the paper alot (the board too). For 500 and 600, I use a spray bottle on the board, but not too wet. I wipe the paper with a wet towel and blow it off periodically. On any of the finer grits, watch out for chunks stuck on the paper which will create swirls. You can sometimes scrape these off with a butter knife. The pad I use for everything after 220 is a homemade 3" thick polyfoam, which allows me to do the rails and not have any edges dig in. Prior to 220, I get everything flat with a Ferro 8" pad.
Ok first, Kids’ don’t try this at home. I learned this from my surfing /Granite laying buddy…he hasn’t electrocuted himself yet? I wet sand with all my grits of wet sand, 220-800. I have a drip bottle attachment, with a pepcock (sp.) valve. attached on the top of the sander. Why? 1) less toxic dust floating around, water & dust just falls right at your feet, water with dust clean up with the Shop Vac in a jiffy. 2) wet paper cuts better and doesn’t gum up when its used wet. Put a couple of squirts of soap in it when you get down to the 400-600 grit, and it will be slippery smooth polishing mirror. Just say no to those little boogers that attach to you sand paper.
You can also just use a spray bottle like posted above. The bad side (not the spray bottle, but water sanding) it is if you have lot’s of pinholes that go through the laminaton to foam you get water intrusion into the blank, plus with everything being shiny all the time you don’t if your beginning to get too close to the weave, so you need to be solid with your lamination skills. Just spray adhesive the grit to a soft pad and start grinding away, it will stick. And kids, make sure you are not wearing your school clothes, you’ll get sludge slung all over your new slacks.
Sounds like your gloss might have kicked off a little too fast, or you worked it a bit too much? Straight gloss resin with a soft 6" Boar hair brush, and give the board at least 5 mins to set and flow out. 5 min to lay and brush out + 5 mins to let sit and flow + 5 min to kick = pull tape at 15
Through the late 80’S and early 90’S, my local resin supplier told us we could substitute waxed Silmar for gloss resin. No matter how slowly I catylized, to the point of too much wax rising, the brush strokes never completely went away. I had always prided myself in being able to lay down the flattest and cleanest glosses that rubbed out to a mirror smoothness, but not with the Silamr. Rhiechold gloss is the only way to go for a reliable finish
I have to agree with Jim on the Reichold Gloss thing.I have no idea why nobody has ever been able to duplicate this product.Silmar is just too slow to kick and the wax-rise is different.I do understand the problems you guys have though…for some reason Reichold is harder to get.On the East Coast I get it from Atlantic Surfing Materials (Ross Houston).One thing about glossing is that folks tend to overwork it or go too thin.One way to get a gloss too thin is to oversand the board.I stop at 120 grit or 150.(we used to stop at 100)If you sand any finer you end up dragging most of the resin off the board when brushing and it won’t flow out right.I cross-stroke twice and “walk it out” with a long stroke going the length of the board one time and no more.On the final pass hold your brush at the metal ferrule with your finger tips and drag it down the board.When doing this final drag you start from the center and work toward the rail.The weight of the brush is enough,also it should be at a shallow angle with the handle leaning toward the direction you are going…You are “flowing” not painting.Sometimes the resin will show brush strokes or ridges after it has flowed out (maybe 5 minutes later).Don’t freak out and try to brush it again,it will level out.The ridges you see are due to a bit of shrinkage as the resin gells and they will dissappear when it gets hard.It’s hard to explain but actually quite easy.Hope this helps you guys. RB
That Riechhold stuff is it Acrylic or epoxy or? I went to there website http://www.reichhold.com/ and there are many choices…who is a supplier for surfboards makers in socal?
Reichold Gloss Resin is Polyester.It has been around for 30 years or more.It has a red to purple color.I think Fiberglass Hawaii sells it.Maybe some of the Cali boys will help out.Note…some distributers repackage it under a different name.For example,Atlantic Surfing Materials repackages it as 'Seacor Gloss Resin". Good Luck my friend. RB
Howzit Mr.Clean, Reichold is the brand the Fiberglass Hi. sells here in Hi… The stuff is getting more and more expensive with every order I make, used to be $25.00 a Gal. Now it’s over $30.00 and and stiil rising. Time to raise the price of gloss and polish jobs. Aloha,Kokua
Kokua,we used to get several shops together and buy a drum.Everyone would bring their own 5 gallon cans and pump out their share.Saved around 50% on the cost.It may be different in the Islands with shipping. RB