Moderated Discussion Areas
  ContinuousWave: Whaler Repairs/Mods
  Polyester resin or epoxy

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Polyester resin or epoxy
beby138 posted 04-04-2001 09:26 PM ET (US)   Profile for beby138   Send Email to beby138  
I'm restoring my 13' 1968 BW and found 6 holes going all the way through the transom (from old engines)filled w/ silicone,i cleaned out now i'm ready to fix it,should i use polyester or epoxy ? Should i fill it all the way thru or add some wood in the middle ? Thanks in advance.
jimh posted 04-05-2001 12:15 AM ET (US)     Profile for jimh  Send Email to jimh     
If the small quantity you'll need, I'd use epoxy. They would have built the whole boat from epoxy resins if they were considerably more expensive than polyester resins.

You can get a nice kit from West Systems for $20.

Or, if you have some polyester resin on hand, use that.

In either case you'll probably just add some filler to
thicken the resin. The West Kit includes some, or just
use sawdust!

Leave a bit of the hole unfilled, then top that off with
straight resin that has been tinted to match the gelcoat
color--or topcoat with gelcoat if you like.

I have an article on small repairs with epoxy at:


jimh posted 04-05-2001 12:19 AM ET (US)     Profile for jimh  Send Email to jimh     
Oops--meant that epoxy is more expensive than polyester. Which is one reason they don't laminate with it in original construction, except in expensive, custom boats.

Also, Epoxy is better for secondary bonding. Jim Watson from West Systems has more advice in the Whaler Radio interview.


lhg posted 04-05-2001 12:47 AM ET (US)     Profile for lhg    
I have never done this, but always assumed that if I ever had to, and the holes were NOT going to be re-used, I would drive in wood dowels, using waterproof glue. If old engine hole was 1/2", I would drill it out to 5/8", just to clean it up, and bevel out the hole at each end to the glass thickness with a countersink. Then glue in the same size wood dowel pre-cut for the thickness of the plywood in the transom. Then a little resin to cover up the ends, same thickness as the glass, and finally the gelcoat topping.

I have used this dowel method to fill in old transducer holes at the lower part of the plywood transom.

When the hole is going to be re-used, I know Don McIntyre like to drill it out, and fill the large oversized hole with resin, then re-drill the same hole in the resin plug. This keeps the wood out of contact with possible water.

dfmcintyre posted 04-05-2001 07:14 AM ET (US)     Profile for dfmcintyre  Send Email to dfmcintyre     
I'd agree with Larrys post, why use a complete plug of resin when your _not_ going to drill through it again. But I'd probably use a wetted out wood plug, wetted with resin instead of waterproof glue, since I've got resin here, but no glue!
beby138 posted 04-05-2001 07:27 AM ET (US)     Profile for beby138  Send Email to beby138     
thanks guys for the replies,the holes are 1/2" and i want to seal it for ever ( I got 4 more for my actual engine)cos one of this open a little tiny door for a non-welcome salt water(no wet foam so far),i like the wet the wood plug w/ resin idea,since i have already both i'll use the west syst epoxy,i'm new boating-whalering and i'm restoring my boat w/ info from this site,
thanks again
Chris J posted 04-06-2001 11:29 AM ET (US)     Profile for Chris J  Send Email to Chris J     
Slightly unrelated question: Were not the older (1970 or so) Whalers laid up exclusively using epoxy resin? Seems to me that polyester wasn't in widespread use back then.
lhg posted 04-06-2001 02:10 PM ET (US)     Profile for lhg    
I think you may be wrong on both counts! Now I may be wrong also, but I have always been under the IMPRESSION that all Classic Whalers were chopper gun glassed, not being layed up with glass matting at all, and that polyester resin was used.

Someone from the factory told me that for the Whaler method of construction, the chopper gun method was better. For any repairs I have made in the glass on my boats, I have yet to see evidence of cloth being used.

Perhaps someone who REALLY knows, can give us the correct information here.

Paint Legend posted 04-06-2001 07:30 PM ET (US)     Profile for Paint Legend  Send Email to Paint Legend     
I've been to few boat manufacturers (not BW) and they are using polyester with chopper guns. Hand laid glass with epoxy is what the high end custom boats/sailboats are made with, its a $ thing. Poster you should get the West System Fiberglass Repair Manual it's the best $ 3.00 you'll spend on repairing your boat. Epoxy is best!

Good luck

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.