Fiberglass repair

[MississippiBoy]

Ok, this is not really a "restoration," just a quick fix (hopefully) on a boat I just bought. It looks like the previous owner bumped a rock or launch ramp or something at idle, and gouged the keel some. According to my limited (very limited) knowledge, I should be able to use some Marine Tex and fix this right up. I'm going to get a keelguard for the boat sometime soon, which would cover this area. But I believe I should fix this first, rather than just slap the keelguard on over it, right?
Question is, what do I need to do to prep this area, and am I correct in thinking that Marine Tex is the way to go? Thanks for the help.


The quarter is supplied as a scale reference, not as an incentive to help me.

[dough4200]

I'm far from an expert, hopefully one will chime in. I had the same looking problem on the pad of my new to me boat. As you, I read on here about Marine Tex and decided to use it. You need to make sure it's good and dry and then prep with some sandpaper. It was pretty easy. I hope I did it right

[BASSCAT7]

First, make sure the repair area is DRY. Leave the boat sit a few days in a dry enviorment, or put a lamp close to it for a few hours to dry it out.

Use the white Marine - Tex.

Clean the chip area real well, lightly sand the edges to remove any loose particles, using a Dremel tool, bevel the edges sloping into the repair area. Make sure there are no ledges.

Tape off the area around the repair.

Stay close to the repair. Make sure there are no tape ends in the sanding area. The purpose of the tape is to avoid a mess and protect the area around the repair from the sand paper.

Mix the Marine -Tex per the instructions, it is a putty type consistency so it will work well on the vertical parts.
Build MT a little over as it will shrink some, if you see any air bubbles pop them gently with a pin..........should be cure in 4 hours, but waiting overnight to sand is best.

Once it is completely cured you can start finishing it.

Use a small sanding block and 600-800 WET sandpaper to get a smooth finish, keeping the paper wet, if sanding lines are still seen up the sandpaper to 1000-1200
If you see a shadow below the sand area you are about to go through the Gelcoat and into the glass and resin. stop sanding.
Once you get the chip sanded smooth you can compound and wax.

When you go to put the keelguard on, clean the keel well with acetone to remove any wax, contaminants, etc.

[Reedbassn]

Just curious but what about Gelcoat? Could you fix this using just Gelcoat? If you use Marine Tex do you apply Gelcoat over the Marine Tex after sanding the Marine Tex or are you done with just the Marine Tex?

[BASSCAT7]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Reedbassn &raquo;</td></tr><tr><td class="quote">Just curious but what about Gelcoat? Could you fix this using just Gelcoat? If you use Marine Tex do you apply Gelcoat over the Marine Tex after sanding the Marine Tex or are you done with just the Marine Tex? </td></tr></table>

Since He is covering it with a keelguard, there is no cosmetic issue so sanding the Marine - Tex smooth is all you need to do.

If you were not covering it, and wanted to match your hull, you would use gelcoat for the repair.

Or, Marine - Tex with a skin coat of gelcoat, after prepping the cured Marine -Tex to accept the gelcoat.

[Reedbassn]

How do you prep Marine Tex to accept Gelcoat Skin coat?

[BASSCAT7]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Reedbassn &raquo;</td></tr><tr><td class="quote">How do you prep Marine Tex to accept Gelcoat Skin coat?</td></tr></table>

Gelcoats are a polyester resin, Marine Tex is an epoxy. You need to apply the Marine -Tex at around a 70 degree air temp, let it cure for at least 48 hours.

If Air temps are lower let cure for 3 - 4 days.

There is a surfactant that comes to the surface when completley cured, an Amine Blush, that will need to be removed so the Gelcoat can adhere to he MT.

Use a dish cleaner type scrubber and clean the surface with warm, soapy water.

Rinse with fresh water.

The MT should not feel waxy when cleaned.

Lightly sand with 120 grit sandpaper, clean again.

Let dry completley then apply the gelcoat as normal.

[Reedbassn]

Thanks BASSCAT7. Sorry to interrupt MississippiBoy. I have the same type of probem.

[MississippiBoy]

It's all good. I imagine this will be my project this coming weekend. I'll post the "fixed" pics once I'm done. Hopefully, they'll be worth posting...