Sanding vs filling hull stratches

#22
Polybrushes are great because they're less expensive. Should dab the gelcoat over the scratches and always make sure that there is a little more than you need. This way when the filing is done there is a smaller percentage of having to re-apply gelcoat and repeat the process over again.

The more heavy duty the compound the more stuff it will take out and the better shine it will give. Super heavy duty is great for taking out the black scuff marks when you get too close to a dock with rubber bumpers in pre-start maneuvering. Gel gloss? I dont know much about that. I've never used it and it has always come out fine. The stuff you found online should do the job very well. I use a different one.... http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtOxfVOXz6EV76EbHSHVs6EVs6E666666-- I think any of them will work well.
 
Thread starter #23
I have poly brushes at home I never use so there is no reason not to give it a try. The link you posted doesn't seem to work, can you check ? thanks again for the useful information.
 
#25
I started applying gelcoat to my hull today. I have a ton of scratches...my hull 21XXX, must have lived on a rocky beach for a few years.

Real Quick: I tried the clear tape on top of the gelcoat and I also tried putting masking tape around the scratch to avoid overspill (less gelcoat to sand afterward). And against all reason, I tried just smearing the gelcoat on the very scratched hull, which actually appeared to work well, however tomorrow I may be hating life.

I'll post my progress and I'm taking pictures along the way. Expect a full write up in a day or two.
 
#26
I start by 'scraping' a very thin coat of gel-coat over all scratches, using a plastic putty knife. Try to leave only gel coat in the scratches, and as little as possible on the surrounding areas. It takes a little bit to get the feel so that you don't drag it our of the cavities, but eventually you will get it to work. To get a nice finish, stop by an auto-body supplies shop; they have up to 2500 grit sandpaper.
 
Thread starter #29
Thanks, I have ball cutters already but I'm wondering if the round shape is appropriate since they always mention to V shape the groove.
 
#30
You don't need to over-think this. I tried a bunch of techniques for scraping out scratches. It comes down to what works well for you.

I couldn't keep the dremel within the scratch and ended up making extra gouges with it.

What ended up working best for me was using one of the points of an old pair of steel scissors.

The more material you remove, the more you have to fill, and the more you have to sand.
 
Thread starter #31
Bjmoose I think your'e right ! I rarely use my Dremel, I prefer manual tools. I often use an Exacto knife I keep dull on purpose for that kind of job (an a lot of others as well that demand any type of scraping)
 
#32
I use a bottle opener for widening plaster cracks, the kind that my family has always called a 'church key'... it's the kind that has the triangular end and the oval end... you know, the one you use to put the triangular holes in a big can of hi-C (back in the day).
 

Merrily

Administrator
#34
A church key ? that's funny
Yup, we called it a church key, too.

Seems like the corner of any scraper would do the job of making a V-shaped groove on the cracks. I've used an old slotted screwdriver on an angle to widen drywall cracks. Ought to work on gelcoat too.
 
#36
Dredies - Yes, I did just that. I scraped the gelcoat over the scratches and kept it very thin...it worked pretty well.

A couple things I noticed were how the gelcoat shrinks as it dries. Deeper scratches may require more than one coat of gelcoat.

Also, it's important to test your gelcoat mix, so that it hardens appropriately. I didn't do this and todays application didn't harden completely, so now I'm entering day 3 of my bottom job and I haven't started sanding yet...haha...
 
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