Trouble with masking tape and Excell blank...

Hey this may be a really obtuse question… but a while ago I shaped a board from an Excell blank that I picked up from FiberglassSupply and I had an insanely hard time getting masking tape to stick to it! I dusted, I ran sticky tape over it to pick up the dust, repeated the process, blew on it… tape just barely held on. The good blue 3M stuff that I have used on several EPS boards without any troubles. In the end I just freelapped the board which wasn’t a big deal as I was using a fairly opaque tint and the board was for me. Still the bottom laps came out definitely a bit more visibly uneven than I would have liked. I almost  tried to cutlap it but it was so loose on the board that I was certain when I did the laps it would just push away in areas, which would have ended up worse than a freelap for sure!

I’m just about to start shaping another board, this one for a friend of mine, using an identical blank and I am wondering if there is something I’m totally missing, if this is just a problem with me, or if other people have had the same issue…? All my others have been with EPS and I never had this problem so I am assuming (maybe hoping…?) that it’s a p/u thing? Or is this something I dreamed up in a foam-dust-induced delusion?

I'll throw out a couple of things and you decide;   1.  Seems to me that just about any kind of tape sticks to EPS, Poly is a differant animal.  I don't recomend Blue tape for Poly.  Stick with 3M 233 or 233+(green).  Even 3M's 2020 Painters tape would stick better than Blue.  The only real problem with 2020 is that it leaves residue on a hotcoated surface, but it is usable directly to foam.  2.  Press your tape down firmly with a seam roller or a thimble along the edge.  It sounds like you took the necessary steps by blowing off the blank etc.  I believe that Excell is an MDI formula.  MDI has its own quirks with regard to tape and paint.    Keep in mind that humidity affects the ability of tape to stick .  The higher the humidity in a room the less likely a tape will stick.   Hope this helps on the next one Lowel 

I have just glassed several of those same excells from fiberglass supply.  they were cheap.  the tape was not a big issue for me though.  I use the 3m 233.( or the green knock off that walmart carries)  the blue stuff never seems to hold well to PU.  It does not have much glue in it.  I think it is mainly made for laytex house paints, and is not meant to be very sticky.  I did find that I had some paint bleed under the tape, even using the expensive 233, so I scored the foam with a razor along the tape, and that helped to eliminate the paint bleed.  I alywasy freelap, so i have no idea how epoxy would effect it, but I recomend you junk the blue tape.  it will just piss you off.



edit:  McDing must have been typing ther same time as i was…

     Howzit bckyle, The blue tape is not the tape to use since it is made with less adhesive so that you can leave it on surfaces for a week. Use 3M 233 or 233+, they work great. Tape has changed down thru the years, back in the 60's and 70's and probably the 80's we used 3M 2050 but it isn't good any more since they have changed the adhesive. Aloha,Kokua

Click the link....I did a Swaylock's advanced search....No Blue tape in Stingray's workshop....:)


Amazing, thanks guys! Sounds like I was totally barking up the wrong tree, had no problems with the tape before but as McDing said, seems like anything sticks to EPS. I’m stoked because I am really after a clean cutlap look on this one. I will pick up some 233 or 233+ asap! …and I will check it out tomorrow evening when I continue w/ shaping.

…cut the outline and put in some basic work on the rocker tonight, hot damn it’s stoking me up so far… 5’8" fish for a buddy, I hope it makes me jealous of him!

…again, thanks much to all, it’s the silly little things that really bog you down sometimes: and that’s why Sways is awesome.

Oh yeah and thx Stingray for the link! Extra info there… I originally had the problem in December, finished glassing the board just before christmas and sanded out at my folks place on the mainland while visiting for the holiday… in the snow, no less! Her first taste of H2O was the chilly kind. Anyway I searched at the time for something and didn’t find any satisfying answers off the bat. Forgot about it… and looks like Rachel had the same problem right after me!

Psyched to have THAT worked out!

Just wanted to revisit the thread in case anyone else is searching for the answer: the 233+ is good, stoked to have that all worked out. If anyone is looking it’s maybe worth mentioning that I couldn’t find it anywhere (resin/fiberglass dealers or hardware stores) for a little while until someone told me it’s a strictly automotive product. So if you’re looking for 233 or 233+, hit up your friendly neighborhood automotive guys.

Thanks again to everyone who chipped in…