gelcoat fix or glass repair first?

[Dhopper71]

Hi all. Been a lurker for a while, but I'm picking up my new old boat tmrw and finally wanted to chime in with a question. I've learned a ton from reading hear already!

I'm getting a '72 AristoCraft 19 that's in pretty darn good shape. Just some cosmetics that I'll be tackling right away (seats, carpet, etc).

My question for you guys and gals is this: There is some cracking and pealng of the top layer around the back portion of the side decks. Mostly on the port side, but there are spots here and there all around. Would this be a gelcoat only type fix or would I need to somehow try to put a single layer of glass down first? I might not get the perfect white match in the gelcoat, but it would certainly look better than the current state.

Any help with which direction to go would be greatly appreciated. Also reading up on gelcoat techniques, so help there would also be great!

Thanks in advance.

David
Cape Girardeau, MO

 

[Cadwelder]

Re: gelcoat fix or glass repair first?

Welcome to iboats Dry Dock...

Anything you have is fixable, but as you may have guessed we'll need some pictures of the damaged area before we can give any accurate advice on the repairs. Need to see what you're seeing.

 

[Dhopper71]

Re: gelcoat fix or glass repair first?

WOW! Too fast for me!

Haven't had enough coffee yet this morning. LOL. Just edited my post and added a pic. I can certainly add a few more if needed, but that is the worst spot around the top and typical of the deck repair I was looking to do. Thanks again!

 

[Cadwelder]

Re: gelcoat fix or glass repair first?

That appears to me as if it's been repaired once before. It looks like way too thick of a layer of gel coat. You'll need to remove all the "flaking pieces and grind down to solid glass to start the repairs. I'm going to see if BWT, Yacht Dr. or Ondarvr will chime in here on this one a they are the resident gelcoat experts here on iboats.

Don't worry I've seen worse here....it can be repaired, just will be a little more involved than a little filling and fairing.

 

[Dhopper71]

Re: gelcoat fix or glass repair first?

Thank you sir. Does look pretty thick, but my experience level is nada in this area of fiberglass. My first thought is remove the loose material, then fill in to level it off with some type of epoxy resin, then finish with a thin gelcoat topcoat. Sound feasable maybe?

 

[ondarvr]

Re: gelcoat fix or glass repair first?

That type of defect is labor intensive to fix because you need to remove all of the bad gel coat and then rebuild the surface back to what it should be. Without being able to examine it closely it's hard to say if it was a repair done after it was removed from the mold, or done while it was still in the mold, but either way the repair will be about the same.

Chip, scrape, sand, or whatever method works best to remove all of the cracked and flaking gel coat and then re-spray it, you may need to fill low areas depending on how much of the surface is removed.

 

[Dhopper71]

Re: gelcoat fix or glass repair first?

Was afraid it would entail more than I originally planned, but I think I'll still try to takle it. I really appreciate the advice so far. You guys are great.

ondarvr - would I fill with an epoxy resin or a glass/resin patch?

 

[ondarvr]

Re: gelcoat fix or glass repair first?

Gel coat doesn't bond all that well to epoxy, so the work should be done with polyester resin and fillers.

 

[Dhopper71]

Re: gelcoat fix or glass repair first?

excellent! so glad we've got access to so much experience here. most of us "guppies" would be lost without you!

 

[BWT]

Re: gelcoat fix or glass repair first?

If possible I would like to see a few more pics; specifically some after you have a section of the loose gel chipped off. I am interested to see if there is anything going on with the fiberglass beneath it (how dry the glass is of resin, if there is any de-lamination going on, etc). If I had to guess it kinda looks like the top layer of fiberglass is a little dry (resin starved) and not creating a good solid surface for the gel to bond to.. But, until a little more exploration, it's only speculation. Try and chip it rather than sand it; it's the top layer that I;m interested, in. Thanks.

 

[Woodonglass]

Re: gelcoat fix or glass repair first?

Well it MAY just be me, but as I look at the pic and I compare the Top color with the color below and then the color below the rub rail it appears to me that the top cap MIGHT be PAINTED over the ORIGINAL gelcoat. Looks to me like the top "Bottom" coat and the coat below the rub rail are and exact color match. But like I said, It might JUST BE ME!!!

 

[Dhopper71]

Re: gelcoat fix or glass repair first?

Thanks again for everyone's feedback.

Hey Wood. I was kind of wondering along those lines too. Couldn't decide if the deck looked faded from years of sun or if it wasn't perfectly matched during a precious re-paint/re-gelcoat job. I'll hopefully be able to tell better once the boat is in hand and I get a much more personal close up inspection. I pick it up Friday. I'll be sure to post up some fresh pics, too.

In either case, I'm trying to figure out the least invasive repair. I'm a bit scared to go chipping off a ton of material. Not sure I have the experience to finish it back off with the right angles and such. My uncle (who has decades of auto body exp.) said to chip it away if it's loose, rough the surface real well, then use bondo. Sand and smooth to the right shape, then prime and paint. Anyone know if gelcoat will adhere to bondo correctly? Has anyone used bondo on minor cosmetic boat fixes?

Dave

 

[Woodonglass]

Re: gelcoat fix or glass repair first?

Well first off, I wouldn't call that MINOR cosmetic fixes. But to answer your question Bondo is a polyester based product and so is gelcoat so they are compatible somwhat. Some/most bondo products are not 100% waterproof and therefore not really suitable for marine use but for above the waterline use can be use in a limited format. I usually avoid bondo and make my own stuff but it can be done. If this kind of flaking is JUST on the top cap I'd recommend sanding/grinding it off and Painting it. I think it would be the easiest and least expensive method. But that's just me.

 

[ingalp01]

Re: gelcoat fix or glass repair first?

I'm with Woodonglass... I'd grind/sand off all of the flaking gelcoat and prep and paint it. If the gelcoat below the water line isn't cracking in the same manner, you can probably just clean and polish that part.

 

[BWT]

Re: gelcoat fix or glass repair first?

I still want to stress the need to figure out the REASON the gel is doing what it's doing. Bondo, paint, gel, etc doesn't matter if the underlying cause is not figured out; more than likely it will just happen again. Could just be an issue of poor quality gel from the manufacturer, but I suspect something more..

 

[Woodonglass]

Re: gelcoat fix or glass repair first?

Yep, it's ALWAYS ALL in the prep.

 

[ondarvr]

Re: gelcoat fix or glass repair first?

That type of failure isn't all that uncommon, it frequently goes along with very thick gel coat and normally multiple layers of gel coat.

I can't tell from the pics if there is more gel coat under the flaking stuff, or if it's glass that has turned white.

If it's more gel coat, the most common cause is the poor bond between layers of gel coat. Gel coat doesn't bond to cured gel coat as well as resin will and the bond is stressed even further when the gel coat is thick, so when the thick gel coat starts to crack it also flakes off.

This bond is compromised even further when either layer is over or under catalyzed. What happens is during the gel coat process there are frequently thin areas where the gel coater failed to spray 20 mils, when this happens gel coat is painted on the surface with a brush right before lamination. In an effort to speed the process the person mixes the gel coat hotter (more catalyst) so it will cure faster, but all too often too much catalyst is added and the gel coat never cures properly and fails.

If it's a repair, it's again the combination of poor bond and thick gel coat, plus a possible catalyst issue (catalyst % is frequently a factor in gel coat failures).

If there is just glass under it, it can still be a too thick, and catalyst problem. When gel coat is too thick it cracks easily, when it cracks water will reach the glass and if the bond is poor it can start to flake off. As the gel coat loses it's bond and the laminate is exposed to the weather it will start to bloom. Blooming is when the strands of glass near the surface start to turn white from water and UV exposure, it can make them look resin starved although it really isn't.

If it is dry glass, the surface will tend to distort some before it cracks and fails, it also isn't normally affecting a large area. This area would also be a low in the mold and resin would tend to flow into it.

But... it can be a combination of any of these....or none of these.....so just take it down to good glass and rebuild it. Try to use a marine type filler if a filler is needed. Bondo can absorb moisture and swell, then crack and flake off just like what you have now. It doesn't always do this, but does often enough to have a bad reputation around water.

 

[Dhopper71]

Re: gelcoat fix or glass repair first?

Thanks again for all the responses! Looks like I'll just have to get the thing in my hands and really dig into it a bit. I'll definitely be posting up some more pics this weekend.

I'll try to run a progressive slideshow from start to finish of what I do to repair it. That way as I go through, hopefully your experience can help me along the way. Probably not doing a full restore, but certainly a good remodel.

I'll keep you guys posted in a couple days!

 

[Dhopper71]

Re: gelcoat fix or glass repair first?

Well, no need to worry about this one. When I got there to inspect and pick up the boat it was much worse condition than any of the pictures represented. Very very disappointing. Apparently all the pics were 2 years old and it had not been taken care of since. Then I found that this area was an obvious poor old repair job and was done on both sides and in a few other places around the deck. The whole boat would need to be sanded/ground down and refinished. The owner failed to mention that he also had this boat stored OUTDOORS in a field UNCOVERED since the end of last season!! Unbelievable.

The boat is still salvageable, but not a project I was looking for. Oh well.

Thanks anyway for all your help. Guess I'll wait until I get a boat in hand next time before wasting your guy's time and knowledge.

The hunt continues.

 

[Cadwelder]

Re: gelcoat fix or glass repair first?

Well, no need to worry about this one. When I got there to inspect and pick up the boat it was much worse condition than any of the pictures represented. Very very disappointing. Apparently all the pics were 2 years old and it had not been taken care of since. Then I found that this area was an obvious poor old repair job and was done on both sides and in a few other places around the deck. The whole boat would need to be sanded/ground down and refinished. The owner failed to mention that he also had this boat stored OUTDOORS in a field UNCOVERED since the end of last season!! Unbelievable.

The boat is still salvageable, but not a project I was looking for. Oh well.

Thanks anyway for all your help. Guess I'll wait until I get a boat in hand next time before wasting your guy's time and knowledge.

The hunt continues.

Don't be discouraged, there are tons of good deals out there....just keep your eyes and ears open.