hull repair help

[skimac420]

Hey folks,

brand new member here and new and first time Grady white owner!! Just bought at 1996 Tournament 225. Pretty good shape but needs some TLC...

first issue I have...hull repair needed on the rear starboard corner. It appears someone else tried to a little patch job but to no avail.

My experience with fiberglass repair is virtually zero but I am willing to learn. I will attach a picture to see what I have. Anyone that can walk me through the steps to repair, I will be grateful!

 

[cedarholm]

I suggest you post this photo on http://www.thehulltruth.com

Lots of fiberglass guys over there.

Grady White customer service may be of help also.

 

[skimac420]

i will do. thanks.

 

[gw204]

Step 1 is to grind or sand off whatever that crap is that was used to make the initial repair. I like a 60 grit sanding drum or flap wheel in my Dremel for stuff like this. After your done sanding/grinding the area mask over the whole thing w/ blue painters tape. The trace around the repair w/ an exacto knife and peel the center out. Whala, instant exact mask. Clean the area w/ acetone. If the damage is deep, you may have to do some spot filling with small pieces of mat or a structural filler (resin mixed w/ cabosil). Then you can apply your gelcoat (spread or spray depending on whether you have paste or liquid gelcoat) over that and sand flush. Once the gelcoat cures, sand flush (careful here as it's easy to sand through the surrounding areas and create another repair for yourself. Slow you sanding once you start digging into the tape. I choose my grit based on how well I did getting the initial gelcoat application flush with the surface. If I did good, I'll start with 220 dry and work into 320 wet, 400 wet, 600 wet, 1500 wet, polish, wax. If I didn't do well, I may start w/ 80 or 150.

Note 1: Pay attention to the gelcoat you buy. Some comes with a surfacing wax already added, some does not. If you get the stuff w/ no wax, you either have to add the wax or once applied, seal it off from the atmosphere for it to cure properly. This can be done with an overcoating of PVA or something simple like wax paper.

Note 2: You can use either polyester, vinylester or epoxy resin if you have to fill any gouges. That being said, gelcoat can be applied directly over polyester or vinylester resin before full cure is achieved. Not so w/ epoxy. Epoxy needs to fully cure and then be sanded for the gelcoat to adhere.

 

[skimac420]

Couple of questions then. Where is the best place to get gelcoat, resin, etc...

How do I best match gelcoat color?

What type of resin would you use? What is best?

 

[gw204]

Couple of questions then. Where is the best place to get gelcoat, resin, etc...

You've got a few choices. For gelcoat you can get color matched stuff online from Spectrum Color or Minicraft, you can buy OEM Grady gelcoat from your local dealer or you can pick up standard white gelcoat and coloring agent from your local retailer. For a faded boat, your best bet is to go with that last option and color match it yourself.

Same thing for resin. There are many online suppliers and you can get it from local stores. I've seen polyester resin at auto parts shops and home stores. Never used that type of poly, never will. If you want "real" poly, look such places as U.S. Composites and FGCI. Same thing for vinylester. I think the same places even carry epoxy. Often times you can get sample kits, which contains small doses of resin, fillers, glass, etc for under $20.

I have personally used vinylester resin from U.S. Composites, epoxy from Raka and epoxy from West System (not West Marine...although it is sold there). At this point, I think my favorite is the vinylester. It wets out mat and cloth very easily.

How do I best match gelcoat color?

Buy straight white gelcoat and a tube of brown coloring agent. When you add the brown, you only need a TEENY TINY amount. Add it in super small doses until you get the color you want. Too much and you have to start over. If you think what you're adding won't make a difference, cut it in half and then cut it in half again.

Don't catalyze it until the color is right. As soon as you put the catalyst in, the clock starts ticking.

What type of resin would you use? What is best?

Best? It's all relative. They each have their benefits.

Poly is the cheapest, has the lowest strength secondary (mechanical) bond to existing structures and is the most prone to absorbing water.
Epoxy is the most expensive, has the strongest secondary bond and is pretty much impervious to water pentration.
Vinylester is right in the middle.

That being said, don't necessarily shy away from poly. That's what the hull was made with, so it's not necessarily bad. Lots of shops use it for repairs.

I've heard people say wood absorbs poly and vinyl better than epoxy.



One other thing I forgot to mention is that resin mixed with cabosil will often leave small pinholes once sanded. Sometimes you gelcoat will fill these, sometimes not. So you may have to "fair" the area before applying the gelcoat. This simply means filling the pinholes and low spots with a compound that sands easily. I've used Evercoat's Formula 27 filler as well as West System's 410 Microlight (mixed w/ epoxy) for this. Both work well, but from what I've heard there are other ones that are easier to use.



Is your head spinning yet???