Gelcoat repair

[1979 Quartermasters]

Hey Guys,

Haven't been around in a while as my boat has been behaving. All winterized and put away for the long winter and needing nothing. I guess I shouldn't be saying that so loud.
On another matter, my friend has rubbed through the gelcoat on his Bayliner and I volunteered to repair it for him. Doesn't seem like the fiberglass has been damaged.There is about 2 ft of damage on the front end of the keel from beaching. I thought I could handle this as I had good luck last time I attempted a gelcoat repair. I have ordered the material required from the same people as last time.
Thought I would ask for a little direction on how to start this repair.

Thanks....

Ken

 

[Rickmerrill]

Yeah Ken don't speak so loud that your boat hears you or you know what might happen.

It looks like you've done similar before so I'll just add clean and abrade and do some faring on the scratches before you gelcoat, then wetsand up through the grits and then buff. Andy at BoatWorksToday has some good videos on gelcoat that might keep you warm while you're waiting for better answers. See http://boatworkstoday.com/video-page

Good luck with the color matching - don't set expectations too high and tell him to quit the beaching or get a hull guard!

 

[1979 Quartermasters]

Thanks for your response, Rick. I've been reading through my old thread and there seems to be some debate as to whether or not the film needs to be applied over the repair. The patch I have to do is about two feet long and the kit I bought didn't supply enough enough film to cover the whole repair. Also I have to wrap around the keel from one side to the other and that will be awkward. Is the film necessary for the gelcoat to cure. I believe the gelcoat is unwaxed as the film was supplied.
As always, thanks.........

Ken

 

[Rickmerrill]

Ken,

I've never used the kit but from what I read I think you're right - the film is used to cure the gelcoat. If the piece they gave you is too small you can tape plastic around the patch. Try to work all the air out it. You might want to experiment with the plastic you pick. In my opinion you want to use the plastic (or wax addative or PVA) if it doesn't have wax in it or it won't harden. You could try a small test on the paste to see if it hardens by itself but I don't think it is going to.

 

[ondarvr]

You don't want to use any plastic film to cover a repair like this, use PVA or wax. You can do it without wax or PVA, but then you need to apply it a thicker and remove the gummy surface with acetone, easier to just use wax.

 

[Rickmerrill]

Listen to Ondarvr, he knows his stuff and I'm sure glad to see him posting!

Ondarvr what is the window for using acetone to remove the gummy surface? Another poster sprayed some unwaxed gelcoat and waited a few days (been about 5 days or so by now). Any chance that trick could still save him?

 

[1979 Quartermasters]

K, thanks guys. I read some where else to use wax paper, so I tried that, in the absence of a response. The gel-coat hardened up nicely. Going to start sanding today. Again, as always......

Thanks,

Ken

 

[ondarvr]

Listen to Ondarvr, he knows his stuff and I'm sure glad to see him posting!

Ondarvr what is the window for using acetone to remove the gummy surface? Another poster sprayed some unwaxed gelcoat and waited a few days (been about 5 days or so by now). Any chance that trick could still save him?

Acetone can be used at any time, it just makes a mess if the repair is very big.

 

[Rickmerrill]

That's great Ken! We're you able to spread it so it was sort of smooth? How'd you do it? Good luck on the sanding!

 

[Rickmerrill]

Thanks Ondarvr.

 

[1979 Quartermasters]

Good morning;

Well, I would say it was a success except for one thing. It's nice and hard, shaped properly and nice and smooth. The only thing I'm not happy with is the colour. I have it sanded at 320 and ready to bring up the shine.

What I'm wondering is, can I put another layer on with a darker shade. It will be 7 days by the time I get to it. It is the keel, so I don't mind the gelcoat being a little thicker.
As always, thanks.......

Ken

 

[Rickmerrill]

Congratulations on getting it this far! As far as bonding you shouldn't have any problems if you scuff it with 120 grit or so but I'm nor sure if you'll have a thickness issue or not. For a single application of gelcoat they say if it is too thin it might not cure correctly and if it's too thick it might crack if there is any flex. If you have too layers and the combo is too thick? No idea.