3m HSRF over gelcoat bond?

[tony]

I used the HSRF very sparingly on my 33. only used it to fill holes that I miss-drilled and also a couple edges to build up 1/8" max.
The question is I've seen a lot of old posts saying it wont stick to gelcoat. I've feathered it onto the gelcoat and it sticks incredibly well. The 3m website shows all the uses for it going directly over gelcoat and feathering in so I cant see the reason for it not to adhere permanently?

Any experts who can weigh in?

-tony

[Jeff Kleiner]

Gelcoat should be taken down with 80 or coarser before applying HSRF or filler.

Jeff

[tony]

I saw another post on the other website about it chipping. Builder said he forgot to sand that portion and a big thick chunk came off. It seems same thing would happen with rage too

[Jeff Kleiner]

I saw another post on the other website about it chipping. Builder said he forgot to sand that portion and a big thick chunk came off. It seems same thing would happen with rage too

Which is why I said what I did in my reply.

Jeff

[tony]

I laid in bed last night worrying about. knowing that I had prepped it all with 80 grit like jeff mentions will help me sleep tonight!

[Presto51]

Gelcoat should be taken down with 80 or coarser before applying HSRF or filler.

Jeff

That my fellow builders is the gospel. Read it, Know it, Apply it.

Ron

[GoDadGo]

Evercoat's Fibertech may be something that you guys might also want to use since it is pretty much approved for all sorts of material like steel, aluminum and fiberglass.

https://youtu.be/r1kavYzXuO8

[Jeff Kleiner]

Evercoat's Fibertech may be something that you guys might also want to use since it is pretty much approved for all sorts of material like steel, aluminum and fiberglass.

Note that the TDS still specifies that the surface must be cleaned and cut with 40-80 grit.

Jeff