Page 1 of 1

WARNING: 3M Blue tape and System 3 epoxy issue

Posted: Mon Jul 24, 2017 7:02 pm
by JimmY
Hi All,

I was putting on the first coat of encapsulation epoxy on tonight, and some areas were "beading up" and not covering well. I kept trying to re-roll the areas but they kept coming back. After looking at it a while I realized what was going on. The epoxy was not sticking to areas that I had masked off while staining the deck.
20170724_213946.jpg
I'm using System 3 Silver Tip epoxy (slow hardener) and used 3M Scotch 2080EL Tape (orange lettering). Wherever the tape was used, the epoxy is beading up. I'm not sure if this will be a big problem, and there is nothing I can really do at this point. The Tans-Tint dyes I used in this area comes off with alcohol, so wiping down was not an option. In hind sight, I really didn't need to rub down the tape since there are "caulk line" between the two colors, and might have gotten away with just lightly applying the tape. I've used this tape since it does not pull up the grain or dye/stains when removing it, but may need to find something else.

My plan right now is to mix a little denatured alcohol in the next coat to hope this will help the epoxy penetrate more, and not disturb the dye. I don't think this will be a big issue, but I'll report back on my progress.

I don't know if other brands of epoxy have this issue, and have not tried other types of masking tape.

Just giving fellow builders a heads up, in the hopes that you can avoid this problem.

Re: WARNING: 3M Blue tape and System 3 epoxy issue

Posted: Wed Jul 26, 2017 6:00 am
by JimmY
Once the epoxy cured, I wiped down the affected area with denatured alcohol and it did not pickup the stain, so I think the epoxy bonded okay. I applied a second coat of epoxy with some alcohol mixed in, and it laid down much better.

Re: WARNING: 3M Blue tape and System 3 epoxy issue

Posted: Wed Jul 26, 2017 8:35 am
by BayouBengal
Nice closeup lighted picture showing precisely what you're describing.

And being able to actually see your epoxy closeup brings me to this suggestion (although you're probably already on it). I realize that I'm looking at the first coat, not your second; but based on that, I'd probably sand with 150 before adding more coats of epoxy. I know that you're concerned about messing up your excellent staining job and I understand because you've put a lot of work into that, but sanding lightly to at least knock off the epoxy peaks will give you a more even and thicker epoxy layer buildup in the end.

Re: WARNING: 3M Blue tape and System 3 epoxy issue

Posted: Wed Jul 26, 2017 9:13 am
by JimmY
Hi Jeff,

We're on the same wavelength. I wanted at least two coats down before sanding, to help prevent sanding through to the stain/dye. I plan to fill the caul lines next, sand, and then build up a few coats of epoxy before clearing it.

The epoxy acts a lot like the WR-LPU where the valleys get deeper and the peaks get higher with each coat! :(

Re: WARNING: 3M Blue tape and System 3 epoxy issue

Posted: Wed Aug 02, 2017 2:41 pm
by Zapped
What a bummer. I haven't worked with epoxy yet, do you think that Glad Press n' Seal or the automotive painter's tape would work better than blue tape? Blue tape and I broke up when I met Frog tape. Frog always worked better for me b/c blue seemed to mess everything up when I would finish furniture - but again, it wasn't on epoxy.

Re: WARNING: 3M Blue tape and System 3 epoxy issue

Posted: Wed Aug 02, 2017 5:15 pm
by JimmY
Hi Zapped,

I would just do a test before you needed to tape anything off. In general, denatured alcohol should remove the residue. In my case, I couldn't use alcohol since the stain/dye I used (Behalen's Solar Lux and Trans-Tint) are soluble in alcohol.