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Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Sun Oct 25, 2015 8:37 pm
by Mr.B
I have acquired a 1970 Boston Whaler 13-foot hull and trailer, no motor. I'm looking to restore it and sell it. It is waterlogged. I I drilled holes and found the water was at the stern. It has been draining for a few months. I can easily pick up the entire bow and raise it up. It is still dripping water out of those holes.

The boat has been re-painted inside and out and needs to be redone. The inside was painted in the original blue. The diamond non-skid pattern is still visible on the deck but everywhere else it has sand-paper-like non-skid.

There are a lot of hairline cracks, spider cracks, not crazing. The outside has some cracks, but not nearly as badly. It was painted yellow on the exterior. I can see what seems to be the original gel coat under that.

How can I fix these cracks?

I really want to avoid sanding the entire interior but the last thing I want to happen is for them to come back and for my paint job to look bad right after I sell it. I want to do it right but not sand the interior if possible. Thoughts.

Thanks,
Brian

Re: Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Mon Oct 26, 2015 12:31 am
by PJMSport15MY1984
You could have the entire inside deck line-x white from a Line-X shop. Good Luck.

Re: Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Mon Oct 26, 2015 1:57 am
by Mr.B
That's an option, but my plan is to paint it the original blue. I found that interlux has color matching the original whaler blue. Thought doing it all original would help the resale value. Thanks though, I may need that luck. :--I laugh aloud--:

Re: Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Mon Oct 26, 2015 8:38 am
by flymo
If you read the old forum, it has many discussions on this subject. The short story is that the cracks really can't be repaired - you need to sand down to the bare glass and recoat. Big job.

F

Re: Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Tue Oct 27, 2015 8:10 am
by cnickm
flymo wrote:If you read the old forum, it has many discussions on this subject. The short story is that the cracks really can't be repaired - you need to sand down to the bare glass and recoat. Big job.

F


As Flymo mentioned. If you want them gone for good you must sand back down to bare glass. This will still not be a permanent fix as it will still do the same thing it is doing now years down the road just like it is now.

You can dremel-out the crazing, re-fill, and fare them, but this is only a temporary fix.

Good luck!

Re: Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Tue Oct 27, 2015 4:27 pm
by Mr.B
Captnickm wrote:
flymo wrote:If you read the old forum, it has many discussions on this subject. The short story is that the cracks really can't be repaired - you need to sand down to the bare glass and recoat. Big job.

F


As Flymo mentioned. If you want them gone for good you must sand back down to bare glass. This will still not be a permanent fix as it will still do the same thing it is doing now years down the road just like it is now.

You can dremel-out the crazing, re-fill, and fare them, but this is only a temporary fix.

Good luck!


Thanks, I've read through the old forums a lot actually. Some people mentioned putting many coats of primekote on to fill them, then paint. I would really like to make this boat look perfect before I sell it, but I don't know if I'm ready for the job of sanding the interior, as I'm sure that will be a pain with all the angles and the non-skid that was used. The bottom is not nearly as bad as the top, and I will sand it down. Should I remove the cracked gel coat areas on the bottom completely and leave the rest alone?

[ Here the TOPIC was changed away from repair of hairline cracks to repair of other problems. Please start a new thread for a discussion of other repair procedures. This will help keep this discussion focused on the original topic. Thank you--jimh]

Re: Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Thu Oct 29, 2015 11:09 am
by jimh
Cracks in gel coat layers usually occur due to stress or movement of the layer. They tend to occur in areas where the gel coat layer has been laid up too thickly.

I don't know of any easy method to permanently and cosmetically repair hairline cracks in gel coat. Since the goal of the repair is improvement in the appearance of the boat for re-sale, I would offer this advice: it will be difficult to make a profit on repair of gel coat cracks on a boat intended to be quickly re-sold at a profit unless you do not put much value on your own labor. Repair of hairline cracks in gel coat is probably not a great method of generating rapid return on investment.

Re: Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Mon Nov 02, 2015 11:50 pm
by Binkster
Hairline cracks or (spider cracks) can't be repaired. The only solution is to grind or sand them off the boat. I wouldn't do too much until I dried the hull out which may be impossible. A dry, bare 13 footer should weigh in the neighborhood of 280 lbs.
rich

Re: Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Tue Nov 03, 2015 2:19 am
by crbenny
There are two choices:

--remove and replace, which is to sand down and re-fiberglass, or

--seal it with LineX marine kevlar coating in Boston Whaler blue.

The latter is the way to go--trust me. If it were something super rare would be the exception. Here is a SPORT 11 Sport I did three years ago. Looked like new when it was done.

Re: Repair of Hairline Cracks in c.1970 Gel Coat

Posted: Tue Nov 03, 2015 8:36 am
by Jefecinco
The LineX certainly looks good and provides a fairly non-skid surface throughout. It even has a shine, or at least the black LineX bed liner in my truck has a nice gloss. But it will never look quite as good as gel coat or two-part paint. Practicality and functionality are its strong points. Not every LineX franchisee has the skills needed for the job. If you plan to use this method, shop carefully. It may not be the most comfortable surface to spend a lot of time with when wearing shorts or going barefoot.