Refinishing a fiberglass top? Options

[KaptKaos]

I have heard folks say that to refinish a top so it's smooth, you need to apply a gel coat to it and sand it smooth.

Anyone have specific instructions on this? What supplies do I need and how best to do it?

TIA

[southernmost914]

Many different ways to do it. Go to your local marine supply stores for West-System, other fiberglass faring supplies and instructions.

Steve (IMG:style_emoticons/default/bye1.gif)

[scotty b]

Block it with 80 or 150 grit. once you see the black texture dissapearing you may want to give it a wipe with bondo to fill any imperfections and get a nice smooth finish. I see no need to lay any more glass on it, the texture is cosmetic, not integral to the top. Sand away

[KaptKaos]

So just use bondo?

[scotty b]

Yeah there's no need in gel coating it. Depending on how quickly and smoothly it sands down you may not even need that. Even if you wanted to you would still need to sand it fairly smooth first before applying the gel coat. If you're worried about it flexing and cracking the bondo you could add some glass to the inside to reinforce it. I have one I started to repair ( hle from a tree limb ) for my dads car. I will be sanding it smooth to paint body color. Maybe I'll take a closer look at it, strength wise, this weekend

[southernmost914]

Scotty, (IMG:style_emoticons/default/pray.gif) I have seen your work and you are" the man". After working with fiberglass for 20 years I can tell you that bare fiberglass needs a barrier coat or it will asorb water and delaminate.( gel coat or a non water asorbing filler such as All-metal )Paint by it self will not do it. The West -System stuff that I mentioned can be sprayed or mixed to a bondo like thickness, is a barrier coat, can be sanded like auto filler, will not crack or delaminate, and is made for bonding with and faring fiberglass. www.westsystem.com (IMG:style_emoticons/default/biggrin.gif)

Steve

[ahdoman]

Joe - Just be careful sanding the finish smooth; don't get into the glass. I was able to sand my previous top smooth (left it flat black though) without going through into the fibers.

[scotty b]

Scotty, (IMG:style_emoticons/default/pray.gif) I have seen your work and you are" the man". After working with fiberglass for 20 years I can tell you that bare fiberglass needs a barrier coat or it will asorb water and delaminate.( gel coat or a non water asorbing filler such as All-metal )Paint by it self will not do it. The West -System stuff that I mentioned can be sprayed or mixed to a bondo like thickness, is a barrier coat, can be sanded like auto filler, will not crack or delaminate, and is made for bonding with and faring fiberglass. www.westsystem.com (IMG:style_emoticons/default/biggrin.gif)

Steve

Nuff said (IMG:style_emoticons/default/biggrin.gif) I've done some minor glass work on cars but if it needs a gel coat so be it. I've always assumed that the primer/sealer I use was enough. Should I consider using actual gel coat on glass cars from now on ? Normally when I strip them I can stay within the original gel coat but on some like that Ferrari kit where I had to repair I counted on the bondo to be my isolation coat.

[scotty b]

(IMG:style_emoticons/default/hijacked.gif) Hey Steve I assume you have boat repair experience ? I may need your help ( knowledge ) with mine at some point. I picked up an early 80's Robalo, one of the good ones, a couple years ago that was hit on the highway. I need to replace the transom as that was where it was struck. I'm a little sketchy about something that major. Is it as big a job as I feel it will be ?

[southernmost914]

Scotty, (IMG:style_emoticons/default/pray.gif) I have seen your work and you are" the man". After working with fiberglass for 20 years I can tell you that bare fiberglass needs a barrier coat or it will asorb water and delaminate.( gel coat or a non water asorbing filler such as All-metal )Paint by it self will not do it. The West -System stuff that I mentioned can be sprayed or mixed to a bondo like thickness, is a barrier coat, can be sanded like auto filler, will not crack or delaminate, and is made for bonding with and faring fiberglass. www.westsystem.com (IMG:style_emoticons/default/biggrin.gif)

Steve

Nuff said (IMG:style_emoticons/default/biggrin.gif) I've done some minor glass work on cars but if it needs a gel coat so be it. I've always assumed that the primer/sealer I use was enough. Should I consider using actual gel coat on glass cars from now on ? Normally when I strip them I can stay within the original gel coat but on some like that Ferrari kit where I had to repair I counted on the bondo to be my isolation coat.

No, I don't think you need to use gel coat. If the primer/sealer being used is a true water barrier coat thats cool, or if the filler is not moisture asorbing and a barrier that's cool also. Just saying westsystem is made to bond ,strengthen,fill and seal glass. (IMG:style_emoticons/default/beerchug.gif)

Steve

[southernmost914]

(IMG:style_emoticons/default/cool.gif)--><div class='quotetop'>QUOTE(scotty b @ Dec 26 2008, 07:32 PM) </div><div class='quotemain'><!--quotec-->
(IMG:style_emoticons/default/hijacked.gif) Hey Steve I assume you have boat repair experience ? I may need your help ( knowledge ) with mine at some point. I picked up an early 80's Robalo, one of the good ones, a couple years ago that was hit on the highway. I need to replace the transom as that was where it was struck. I'm a little sketchy about something that major. Is it as big a job as I feel it will be ?
[/quote]
Depends on the damage, but yes, the most critical part of the boat if it's a outboard. Can be a major job .Pm me photos if poss.

Steve

[KaptKaos]

Joe - Just be careful sanding the finish smooth; don't get into the glass. I was able to sand my previous top smooth (left it flat black though) without going through into the fibers.

I tried sanding another top, bit it never got smooth. Whatever it was coated with was there solid. I would up using bedliner spray on it, which works well, but it's not really what I want.

I think I will look into this west system.

[geniusanthony]

I would think that a flexible filler would be good for a top. It may have been mentioned and I missed it but there is flex when you push down on the top of the um errr top.

[RoninEclipse2G]

Nuff said (IMG:style_emoticons/default/biggrin.gif) I've done some minor glass work on cars but if it needs a gel coat so be it. I've always assumed that the primer/sealer I use was enough. Should I consider using actual gel coat on glass cars from now on ? Normally when I strip them I can stay within the original gel coat but on some like that Ferrari kit where I had to repair I counted on the bondo to be my isolation coat.

Bondo and primer/sealer is fine for isolation. Gel coat is mostly for the manufacturing process, being a surface to adhere the release wax to so that things will pop out of the mold smoothly. in fiberglass manufacturing you gelcoat the mold and polish it with a release wax, afterwards you re-gelcoat on top of the release wax and then lay your glass inside. it helps everything come apart smoothly. good sealer/primer is all that's needed after that

[southernmost914]

I would think that a flexible filler would be good for a top. It may have been mentioned and I missed it but there is flex when you push down on the top of the um errr top.

No, It doesn't flex when you push down on the top. Only when you sit in it. Drive it . Remove it. Store it in the trunk. Jack it up and put it on your jack stands ect........

(IMG:style_emoticons/default/av-943.gif)
Steve

[VaccaRabite]

I did mine with 80 grit sand paper on an air board sander.
I did not re-gell it.
I might have used a little bondo, but I kinda don't think so. I remember being worried that the top might flex and break the bond with the body filler.

I did reseal it with epoxy primer before I painted.
(IMG:http://farm3.static.flickr.com/2142/2067451842_e4f167bd4f.jpg)

Zach