Al;

I am patching up some cracks on the interior hull of the Wayfarer, around the ribs. Can epoxy resin be used on the glass reinforced plastic (GRP)? If not, what does one use? Tried a small patch and the epoxy didn't hold.  The test area was roughed up just lightly, by hand.

Anastasia
 

----- Original Message ----- 
From: Al Schonborn 
To: Anastasia  
Cc: Ton Jaspers ; Jesper Friis ; Jens Konge Rasmussen ; Ian/Mike Porter ; Hans Gottschling ; George Blanchard ; Earl Schnur W1028 
Sent: Tuesday, May 20, 2003 9:32 PM

Hi, Anastasia:

To the best of my knowledge, you should be OK to epoxy over fibreglass. Will copy to a few guys who should know for sure.

Uncle Al (W3854)
 

----- Original Message ----- 
From: Jesper Friis 
To: 'Al Schonborn' 
Sent: Wednesday, May 21, 2003 5:04 AM

Hello Al,

This question is easy to answer when you have spent hours ruining your boat!!!!!!!!!!!!!!!!!

The answer is that it is possible to use Epoxy on Polyester, BUT IT IS NOT POSSIBLE TO USE POLYESTER ON EPOXY.

Best Regards

Jesper Friis
B.Sc. (Naval Architect) 
 

----- Original Message ----- 
From: Konge 
To: Al Schonborn ; Anastasia  
Cc: Ton Jaspers ; Jesper Friis ; Ian/Mike Porter ; Hans Gottschling ; George Blanchard ; Earl Schnur W1028 
Sent: Wednesday, May 21, 2003 5:57 AM

Hej Anastasia,

Epoxy resin should to my best knowledge work, but I would use a thin layer of glassfiber with polyester, to keep the same material as the hull. Essential, whatever you decide to use, be sure the repair area is clean. I normally use an angle grinder to remove the surface, and afterwards clean up with acetone.

Hope you will succeed!

W-hilsen 

Jens Konge Rasmussen, SWS, Danmark
 
 

----- Original Message ----- 
From: Secretaris 
To: 'Al Schonborn' ; 'Anastasia' 
Sent: Wednesday, May 21, 2003 1:33 PM

Hey Anastasia,

Even over here in Holland (Europe), I have read about your encounters with the Wayfarer community and especially with Lee Hughes. We (the Dutch Wayfarers) are always happy to welcome a new 'family' member.

I have some experience with epoxy and unfortunately Uncle Al found out about that ;-) So here is my $0.02

Polyester has always a coating at the outside. On the outside of your hull that would be the gel coat but on the inside there is a coating as well. Not gel coat but something else but I can't remember how it is called in English, but that is not important. Furthermore, there may be one or more layers of paint. Epoxy won't hold on paint or the protective coating. Even if it seems to hold it will tear off eventually.

The best approach is to sand away all coating products until you reach the glass fibres. Then clean thoroughly with acetone or xylene solvents (available from your epoxy supplier). Just to be safe, use lots of clean towels (I use one or more rolls of kitchen paper). If you use the same towel over and over again, there is a risk of moving the contamination instead of removing it. Finally when all dirt and grease have been removed, clean it again, just to be sure.

Now you can apply the epoxy and glass fibre. Epoxy and glass fibre gets rock hard while epoxy alone will never be strong or hard. It is OK to use on small scratches but for serious repairs I would always use glass fibre in combination with the epoxy. The easiest to use and strongest is woven glass fibre. For nice finishes, use 150 grams per square meter but for strong repairs, use 300 grams cloth. And if it needs to be very, very strong, use several layers of glass cloth and epoxy.

Now comes the tricky bit. There are two religions in Epoxy-land. The one says you should apply a second layer while the first is still tacky. Doing so will cause the two layers to polymerise together into one. Many manufacturers advise against this method for it could have some nasty side effects. I don't know what they are, since I never tried it. I belong to the second religion that waits with a second layer until the first one has completely cured. Not only is this the preferred method advised by most epoxy suppliers, but it also allows me to have a normal life and a beer in between layers. Using this method you need to clean the surface of the first layer with acetone or xylene before applying
the second. This is very important since a very thin waxy layer usually lies over the epoxy that prevents the second from connecting with the first layer. Also, it can't hurt to roughen the surface up a little with sandpaper for even better adhesion of the second layer. Cleaning with solvent again after sanding is very important.

Never use white spirit or thinner, these products do not go well with epoxy.

Please bear in mind that I am just a hobbyist, like you. Others may have another and perhaps even better solution. I can only say the above has worked for me. Careful reading of the instructions that come with the products (twice) also helps, and remember not all products are the same nor is the way to use them. Epoxy is a family name and many differences exist between individual products.

Hope this helps.

Best W-wishes from Holland,

Ton Jaspers (W5011)
 

PS: Small scratches I often cosmetically repair with some gel coat coloured with pigment (ask for a gel coat repair kit at your local chandler). This works particularly well on the outside of the hull where everyone can see. First (again) sand and clean (as always). Then a blob of gel coat, and when it has cured, sand it into shape, first rough then gradually with finer sand paper, 600 and eventually 1200. Then finish off with car cleaner to get a good shine again. It is as easy as it sounds.

T
 

----- Original Message ----- 
From: Al Schonborn 
To: Anastasia Hopkinson W2639 
Sent: Wednesday, May 21, 2003 8:07 AM

Well, Anastasia, there you go. See what a helpful bunch our guys are!!??

Uncle Al (W3854)