SMC Hull Repair Help Needed

Gentlemen,

I'm a new member. I just bought a Yamaha Waverunner that the hull was beached number of times and has worn out. Please see attached pictures.

After doing research, I found out Yamaha hull is made of SMC material and not gelcoat.

Could experts here help me/guide me in the right direction of how to repair this so I wont have to worry about it. I was told to buy Evercoat SMS Resin and 1.5 oz fiberglass mat.

I would appreciate any help in detailing what I need to do. Unfortunately I will have to lie down under the trailer and perform the work.

BTW, I realize this is boat forum and I consider this a boat for those who can't afford the bigger ones

Best,
Captain R

 

Welcome Cap'.
I would not use polyester to patch it. Use epoxy resin and cloth built up in sufficient layers to reach original thickness. There are several threads on this forum on how to do the work. After curing the patch may be ground, sanded and polished to match the original contours. You can add black universal pigment to the epoxy so it will better match the original.

http://www.amazon.com/s/?ie=UTF8&ke...vpone=&hvptwo=&hvqmt=b&ref=pd_sl_3hmmq55qje_b

See http://www.boatdesign.net/forums/boat-building/boat-repair-20192.html

 

Isn't the SMC resin epoxy base?
Should I use cloth for this contour or mat?

They said the SMC resin comes with a hardener and is the perfect match for this hull but also I was told west system epoxy would work just as well.

Anything that works is fine with me if I can find it locally...

 

SMC is polyester according to what I found. I would use cloth in layers rather than mat. I have had good results using West System epoxy.

 

http://www.evercoat.com/productDetail.aspx?pID=16

"SMC resin is a polyester-based resin used for repair of SMC and fiberglass panels and parts."

 

Thanks for the reply. I can go to west marine and buy the west system epoxy. Do you know how much I need for a job this size?

Also what weight cloth, 1.5 oz?

Thanks again

 

Yes, that's the one I was told to use. Should I use that or west system epoxy?

 

How much area and thickness do you need to grind out to reach undamaged hull?

I would use cloth between 6 and 10 oz. weight.

 

I would use the epoxy.

 

I have repaired dozens of them with polyester and it worked fine. Years ago I had a series of jetski rental business customers and they had damaged boats on a regular basis. The paint is urethane, and you can go to any auto paint supply for it.

 

This could be worth a throught

For a few years i made surflife saving boats and at the end of each season we used to get the boats in for there mantinance checks and repair the bottoms like what you got !!,after some thought i used vinylester resins and fortified the resin for the glass with Fine carborundum powder . The carborundum grit is whats used in sand paper!!! comes in all sizes of grit the finer we impregated chopped strand matt with and then found a sanitary ware gelcoat that was really hard and mixed the same girt with that but a lot more and sprayed it on the surface of the csm and did a couple of healthy coats . When it was hard it was impossible for a grinder to do anything but scratch the surface . years continual draging up the beach wore out the surface still but instead of each year we got 4 years before having to scuff and clean the surface and respray only not repair . so worth a thought !!! Carborundum is available from 3M and the grit size was the same as used on 230 sand paper !!! the 150 grit for the outer surface . after a while we manufactured the boats with the grit in the standard gelcoat just as a part of the production . and that reall improved the wearability also silica sand can be used but the git size is bigger and cant spray it . We over the years even used combinations of silica sand and carborundum on the flanges of moulds to stop guys from grinding the edged away . a grinder with a new disc just slides over the top .
In your case the bottom of the hull is black so if you finished with black tooling gel coat and the carborundum mixed in you wouldnt see it hardly !!
simple fix "DONT RUN UP ON THE BEACH "!! It might look cool but cool has a price tag !!

 

tunnels:

Thanks very much. I don't beach my skis. I do offshore riding. Dana Point to Catalina, it's about 76 miles round trip. I have over 100 crossings. I bought this ski in this condition and am worried about it so I like to fix it. Owners were bunch of drunk people, I am not kidding you....

So is this gelcoat mixed with carborundum? Is gelcoat going to stick to SMC hull? I'd love to spray instead of laying up cloth and sand and sand....

Did you mix the paint in gelcoat as well?

Thanks so much!

 

Thanks so much for the info. Do you think I can roughly have them match the paint without me chipping paint off the surface?

 

I can add black pigment to epoxy? is this something I can buy from west marine with their west system epoxy? I really like the idea having the paint in epoxy a lot better than spraying it as I have to do the work laying down under the trailer..

 

You can get color sample chips from the paint store and find whatever matches close enough.