Motorcycle Racing Forum

Motorcycle Talk => Wrenching => Topic started by: proechel539 on July 10, 2013, 07:19:23 PM

Title: Fiberglass repair?
Post by: proechel539 on July 10, 2013, 07:19:23 PM
What is the best resin to use and is it better to use mat or woven glass for an inside repair? Just want a few suggestions I have to get busy this weekend on some body repair. Thanks
Title: Re: Fiberglass repair?
Post by: proechel539 on July 11, 2013, 09:13:16 AM
Never mind found a good article on the WERA forum, from sport rider.
Title: Re: Fiberglass repair?
Post by: F2RGK on January 30, 2014, 08:58:17 PM
Use SMC resin and stranded fiberglass not the woven stuff.  Grind out the damaged areas and patch away.
Title: Re: Fiberglass repair?
Post by: EX_#76 on January 21, 2016, 11:29:03 PM
Us composites makes great resin, they are on the web.  Vinyl ester is quite a bit stronger than poly ester but either will work fine.  Don't cheap out on the resin, their premium polyester is real nice resin.  I typically use fiber glass mat for repairs.  Grind the area back at an angle.  This yield a larger area to bond to.  For best results you need to have at least 1 inch of the Matt overlapped on the undamaged area.  Grind or sand all surfaces you want to bond to.  Then, Wipe the area down with acetone prior to applying the mat and resin.  Do not over catalize the resin.  The faster it cures the weaker the bond.  2 layers of 1oz Matt should give you a nice strong repair.  Apply the resin on the mat with a paint brush by dabbing.  If you attempt to paint the resin on you will make a mess if the Matt as it will slide or mush all around.  Just get it wet and wait for the resin to devolve the binder in the Matt.  Once the binder has broke down it will conform to the shape with a little more dabbing.  I also prefer to tear the Matt rather than cutting it.  I find that it blends to the shape better that way.


Good luck
Guy
Title: Re: Fiberglass repair?
Post by: backMARKr on January 22, 2016, 01:09:05 PM
Quote from: EX_#76 on January 21, 2016, 11:29:03 PM
Us composites makes great resin, they are on the web.  Vinyl ester is quite a bit stronger than poly ester but either will work fine.  Don't cheap out on the resin, their premium polyester is real nice resin.  I typically use fiber glass mat for repairs.  Grind the area back at an angle.  This yield a larger area to bond to.  For best results you need to have at least 1 inch of the Matt overlapped on the undamaged area.  Grind or sand all surfaces you want to bond to.  Then, Wipe the area down with acetone prior to applying the mat and resin.  Do not over catalize the resin.  The faster it cures the weaker the bond.  2 layers of 1oz Matt should give you a nice strong repair.  Apply the resin on the mat with a paint brush by dabbing.  If you attempt to paint the resin on you will make a mess if the Matt as it will slide or mush all around.  Just get it wet and wait for the resin to devolve the binder in the Matt.  Once the binder has broke down it will conform to the shape with a little more dabbing.  I also prefer to tear the Matt rather than cutting it.  I find that it blends to the shape better that way.


Good luck
Guy

TRUST NOTHING THIS MAN SAYS!!!


Hi Guy! :biggrin:
Title: Re: Fiberglass repair?
Post by: EX_#76 on January 23, 2016, 10:08:09 AM
Thanks....jackass!!!




How's life mark?
Title: Re: Fiberglass repair?
Post by: bruce71198 on January 24, 2016, 12:58:24 PM
Quote from: EX_#76 on January 21, 2016, 11:29:03 PM
Us composites makes great resin, they are on the web.  Vinyl ester is quite a bit stronger than poly ester but either will work fine.  Don't cheap out on the resin, their premium polyester is real nice resin.  I typically use fiber glass mat for repairs.  Grind the area back at an angle.  This yield a larger area to bond to.  For best results you need to have at least 1 inch of the Matt overlapped on the undamaged area.  Grind or sand all surfaces you want to bond to.  Then, Wipe the area down with acetone prior to applying the mat and resin.  Do not over catalize the resin.  The faster it cures the weaker the bond.  2 layers of 1oz Matt should give you a nice strong repair.  Apply the resin on the mat with a paint brush by dabbing.  If you attempt to paint the resin on you will make a mess if the Matt as it will slide or mush all around.  Just get it wet and wait for the resin to devolve the binder in the Matt.  Once the binder has broke down it will conform to the shape with a little more dabbing.  I also prefer to tear the Matt rather than cutting it.  I find that it blends to the shape better that way.


Good luck
Guy
Thanks for that Guy, Over the last few days I have used some of these techniques you mention and what a difference it has made over my former.
Title: Re: Fiberglass repair?
Post by: Eskimo on January 25, 2016, 07:06:32 PM
Quote from: EX_#76 on January 21, 2016, 11:29:03 PM
Us composites makes great resin, they are on the web.  Vinyl ester is quite a bit stronger than poly ester but either will work fine.  Don't cheap out on the resin, their premium polyester is real nice resin.


In checking out their site, they mention that the polyester resins are more brittle than the epoxy resins.  I would think this flexibility of the epoxy resins is a desirable trait?


Just trying to understand better.  (By better, I mean..at all. :) )
Title: Re: Fiberglass repair?
Post by: bruce71198 on January 26, 2016, 11:20:03 AM
Quote from: Eskimo on January 25, 2016, 07:06:32 PM

In checking out their site, they mention that the polyester resins are more brittle than the epoxy resins.  I would think this flexibility of the epoxy resins is a desirable trait?


Just trying to understand better.  (By better, I mean..at all. :) )

Think dropping a glass dish on concrete as compared to dropping a tuperware lid on the same surface.
Title: Re: Fiberglass repair?
Post by: EX_#76 on January 26, 2016, 05:53:41 PM

Glad I could help Bruce!!!  Dabbing the resin on the mat really helped me to get a nice even layer on the repair.

There are many different recipes for epoxy and polyester.  The real answer on flexibility and strength is, it depends on the amount of the individual ingredients that make up the resin.  In what they are stating about their epoxy and polyester may be true, and also mat not apply to another brands resin.  Honestly, US composites premium polyester is pretty darn flexible when the part is finished.  It offers a little give than other resins I have tried, when a crash occurs, will it still break, yes. 


There is nothing wrong with epoxy, it has a much lower heath hazard than the esters.  Epoxies will not work with standard fiberglass mat as it can not break down the binders that hold the mat together.  There is a company making epoxy compatible fiberglass mat but i have never used it. 


I would not get too hung up on the type of resin used as related to the strength.  nearly all of the strength in a laminate comes from the material, not the resin. 


Keeeeepppppp Dabbing!!!!!!!


LOL
Guy
Title: Re: Fiberglass repair?
Post by: backMARKr on January 26, 2016, 10:42:40 PM
Quote from: EX_#76 on January 23, 2016, 10:08:09 AM
Thanks....jackass!!!




How's life mark?

Pretty good! Got a lil one running around the house and back to racing regularly finally.

How's life up north?