That never occured to me wrc. Can anyone verify pushing contaminants into sanding grooves. I’ve seen plenty of epoxy disasters here from people using solvents. I’ve never had one tho I’ve had a few minor spots on epoxy fill coats.
IPA’s get me too drunk. Two max. I don’t mind the buzz, but think life is too short to waste one day of it with a hangover. Tribute beers taste the best wrc. Cheers. Mike
There goes that foot again.
Regarding contaminants pushed into grooves sanding ontainated surfaes, at least twice, that is the only logical reason I feel I was able to partially lift off a epoxy saturated reinforcement I have done on the decks of boards. They were sanded to 120 or rougher with sharp paper, but I had not thoroughly wiped with some sort of solvent beforehand , just gone at them with that sharp paper only to find the bond weak once cured
Now I dont take the chance. I often add patches to bridge soft spots developing on the deck of my HWS’s, and the one foam board I still ride. I do not always dewax the whole board, but I do remove off a good portion surrounding the ding/area needing reinforcement . Napkins saturated with 91% Isopropyl/ or DNA come up with brown marks where my fingers were scrubbing the deck when it appeared the deck was completely free of wax. from scraping alone.
Perhaps its overkill, but secondary bonding issues are so much more work to fix than insuring they do not/cannot occur in the first place, so even if I’m rushed to get it my board reinforced for the next session I do not sand before that napkin/paper towel comes up clean and not shiny, inspected under a strong light. I pretty much have taken to wearing a 30/150/600/2000lumen headlight(O-light h2r) on my head for just about everything now, and some reading glasses.
I do not(yet) need reading glasses to read, and my workspace lighting is hardly inadequate anymore. The headlamp just reveals so much more. 600 lumen is almost too bright, 150 not quiet enough in my opinion, but Im also rarely looking at white foam.
I could of swore I read about sanding contaminants into sanding grooves which then can possibly impede secondary bonding in System3’s ‘The Epoxy Book’ but just gave it a quick once over and did not see mention of it:
I had little experience with other brand epoxies than system three, but when I gained some fisheyes became an issue, and so I take no chances with contaminents, not just with fill coats, and getting contaminents in sand paper is also something I try really hard to avoid, as I am not good at throwing away sandpaper when I should
Standard advice for amine blush is to remove with soapy water, rinse thoruoghly with fresh water and dry – before coarse sanding for keying. This is to avoid sanding the blush into the finish and later bonding problems. I would not want to sand anything into the finish that could affect bonding.
A good IPA is hard to beat. Like wrc, I usually chase an IPA with a standard commercial American brew. But I have been known to follow an IPA with a good English style bitter for a nice mellow overall hops buzz (gotta love lupulin). In 20-20 hindsight, getting wasted was never worth the hangover.
I am not an Epoxy expert. But I feel pretty comfortable with the method I described considering lemat does the same. Low Odor Mineral Spirits is not that toxic and takes the residue off easily.