bonding to poly resin ??

[onenomad]

When using polyesther laminating resin, is it necessary to scuff up the first (saturation) cured coat before recoating and laminating? I am used to using non-blushing epoxy, and scuffing isn't necessary with it. Also, when using epoxy to bond mat/cloth to cured laminating poly resin, do you have to scuff the poly to make that bond? I have several areas where cloth/epoxy laminations meet cloth/poly lams, and want to make sure that the bond integrity is complete. Can anyone make sense of my post? I know what I mean to say, but it sure looks like gibberish when written. Thanks for any help.
Gerry

 

[ondarvr]

Re: bonding to poly resin ??

Any old polyester surface should be sanded before anything is applied to it.

Sand it thoroughly before applying the epoxy and it will stick very well.

Polyester to polyester, yes it needs to be sanded if there is wax in the resin, or it sat for a few days since the last layer. If you're doing the next layer the same day or in the next day or two, you don't normally need to sand it.

 

[erikgreen]

Re: bonding to poly resin ??

By the way, even if you're working with non blushing epoxy, it's still not a bad idea to scuff and clean the surface before applying another layer if you're doing it on top of a fully cured epoxy surface.

Basically, if it's cured you're only getting a mechanical bond. Epoxy will do a mechanical bond much, much better than polyester, but it's still weaker than it could be if you don't scuff it up and make sure the surface is clean. The scuffing creates more surface area for the epoxy to bond to, and may also create a dovetail effect on a microscopic level, as the new epoxy hooks around and under the old.

Erik

 

[onenomad]

Re: bonding to poly resin ??

OK, Thanks for the info. Looks like ruffing up is in order, on both resins.
Gerry

 

[oops!]

Re: bonding to poly resin ??

after two days....ruff and scuff the whole shabang......clean with broom...then vacume totally clean...then acetone...then glass.....= good bond

 

[drewmitch44]

Re: bonding to poly resin ??

"shabang" Thats my word. I brought that back out of the grave the other day in your thread oops. LOL just messin with ya. You must have liked that though. Shabang! LOL

 

[onenomad]

Re: bonding to poly resin ??

Hey, oops!,
Went to my supplier to stock up on "shabang". It is temporarily on back order. Just my luck.
Gerry

 

[oops!]

Re: bonding to poly resin ??

Hey, oops!,
Went to my supplier to stock up on "shabang". It is temporarily on back order. Just my luck.
Gerry

gerry we have a store here called canadian tire.....

the shabang's are kept reight beside the kit and kaboodle's....

 

[onenomad]

Re: bonding to poly resin ??

oops!, re:Canadian Tire,, ha,, I'll bet you're right. I have heard they carry most everything. Kind of a long drive for me tho. I might have to substitute with "the whole Mary Ann".
gerry