glassing tops of stringers

[jc55]

Hey guys, I've done some searching and read some great tips on glassing the tops of stringers. From rounding them to adding wet strips right before decking, etc. My stringers are all in and tabbed on the '68 C-Gull... all the way up the sides leaving just the tops covered in resin only(marine plywood stringers doubled up). I'm painting all of the stringers and inner hull with Sherwin Williams Duraplate 235 epoxy, filling with 2lb expanding foam(thanks jigngrub), then decking. Will painting the tops and sides of stringers with the epoxy paint do the job or must I glass the tops of the stringers as well for strength? Thank you for any input.

 

[jigngrub]

Re: glassing tops of stringers

Are you using epoxy resin or polyester?

 

[jc55]

Re: glassing tops of stringers

Polyester resin on everything inside the hull. Top coating with 2 part epoxy paint.

 

[Woodonglass]

Re: glassing tops of stringers

I'd put at least one layer of CSM on but. Back in the day a lot of the mfg's did nothing. It's up to you. It about sealing not strength

 

[jigngrub]

Re: glassing tops of stringers

If you have resin on top of the stringers I'd glass them over and then paint, if there isn't any resin on the tops you could probably get away with 3 or 4 coats of the epoxy paint. I say this because without the cloth/mat poly resin is weak and will flake off over time and you don't want flakey junk under your nice epoxy paint.

Update your build thread with some pics of the painted inside of the hull, I'd like to see it.

 

[jc55]

Re: glassing tops of stringers

Ok great you guys! I think that I will take the best of both worlds and lay a strip of resin soaked 1708, the width of the stringer, on top. I'll try to add some pics tomorrow night Thanks!

 

[ondarvr]

Re: glassing tops of stringers

Epoxy paints tend to not be as good as just epoxy, so I wouldn't trust it as a sealer.

 

[ondarvr]

Re: glassing tops of stringers

Also, what advantage do you expect to see in painting all of the glass in the bilge?

 

[jigngrub]

Re: glassing tops of stringers

Also, what advantage do you expect to see in painting all of the glass in the bilge?

I think it's going to give the foam something pretty to look at while it's laying on top of it!

 

[glenn property of pam]

Re: glassing tops of stringers

on mine I used 1708 cut about 2" wide then I stretched it a little length ways so it distorted the weave then it went over the top of the stringers with out much of a problem. I did consider making a jig with a piece of scrap wood with a couple of 2 by 2 nailed to it so there was a gap just over 3/4 wide (stringer width+fiberglass+ a little extra room for the new cloth) then put a wet strip 4" wide on top of the stringer cover with a strip of wax paper then push the jig down so its held in place until the resin sets. but my wife got the wrong type of paper so I just stretched the 1708 instead.

 

[jc55]

Re: glassing tops of stringers

Great idea glenn!

Ha ha, I'm using epoxy paint, long and short, to keep water from immediately penetrating between the hull and tabbing and seeping into the center stringer. Looking at the ant infested, mulched center stringer, but yet rock solid deck, decent transom, and side stringers leads me to believe that water sits in that lower forward bilge and finds it's way to the wood. Since this boat will be kept in the water most of the time, I can keep on eye on water pooled below decks and keep up with it. Epoxy is used on tank containments and pipelines regularly so I'm hoping I can buy some more time

I got the tops done. I think I have enough air trapped in it to keep this thing afloat...maybe even air up the trailer spare in an emergency. I laid strips on the side stringers and went 5" wide on the center stringer. This is "pre covering the tops". Didn't want to post THAT picture!

 

[ondarvr]

Re: glassing tops of stringers

The epoxy paint will be of little value, if you want to seal it better use straight epoxy (at least 2 coats). The reason for the rotten wood is typically from poor workmanship and design, not so much the resin. Your work will probably be much better than what was done when it was built.

Leaving the tops of the stringers unglassed would be one of those mistakes that allows water to find the wood. Also polyester laminates should be thoroughly sanded before epoxy is applied over them, the tacky (uncured) surface doesn't give a good surface to bond to because of the difference in the chemistry.

 

[jc55]

Re: glassing tops of stringers

Thank you ondarvr for the great advice. All of this is still unknown territory for me, but I'm determined to get it. I'm letting it cure for a couple of days under light heat and will sand her down with a D/A before top coating it. Thank you!

 

[glenn property of pam]

Re: glassing tops of stringers

If I had to guess you have seen some very small air pockets in the fiberglass (white spots) and you are worried that water could in many years find away in. Epoxy paint would be a easy to use sealer but epoxy and poly are not the best of friends so you will not be able to get a good bond to any place you have painted. in the area you are planning to paint it shouldn't matter as you are not bonding any more glass to the stringers. A coat of epoxy paint or gel coat will not add much weight or cost compared to sleeping better at night so I think you should go for it. Just don't go crazy and paint a area that you are bonding to later or you will be causing extra work sanding it back off.