What kinds of gel coat?

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#1

My dad has been impressed with the repairs I’ve done on fiberglass bodies and he wants me to repair some rock chips in the white gel coat in his Ranger boat. I’ve repaired gel coat on an old personal watercraft and it turned out really well, but this is a $30,000 Ranger boat and I want to do it right.

I don’t want to find out that the polyester gel coat I used chipped off because this was some sort of special fiberglass contruction that I’m not aware of. I haven’t seen the chips yet, but he told me “it has chipped through the gel coat and you can see the black mat reinforcement”. He said there is no wood in this boat and I’m wondering if this is some sort of core material that might need more than just a shot of gel on it…

So have y’all heard of “black” mat? Any idea what that is?

And will regular PE gel coat be good enough? Are there different “grades”? My regular supplier (fiberglasssupply.com) doesn’t have epoxy gel coat. Should I be looking for that? I’ve never used epoxy gel coat – is it the same when it comes to application?

Whenever I need gel coat, I just order the plain white stuff and tint it if I need to. That has always done me well, but this isn’t something I can do wrong. He’s helping me by paying me (cause our finances are in bad shape) and I want to do this perfect the first time.

#2

I contact Ranger and it sounds like a regular PE gel coat is what they recommend. :slight_smile:

#3

Thats a good tip - go with Ranger’s plan - but I’d bet you that 99.99% of marine aps are polyester gel - unless you really get “TOP END/ONE-OFF.”
SO Ranger is back in the business? Glad to hear that - I have not been watching the US market for a while Thought they went under way back late -70s.

Black Mat? Maybe black fiberglass - www.fiberglassite.com sells some fine weave cloth and other outfits do to. Is that what you mean? OTOH – I doubt thats what you are seeing as core though. It may just be roving that they sprayed black - or has discolored picked up dirt and grime - just hope its not MOLD in that area - you’ll want to clean that bit if you can.

For the repair - I’d do as you have outlined - mix the white with tint to match as close as you can. Also you can feather it in with a little work. Sounds like you want to do a nice job for your Dad - good on ya!

#4

LR, it sounds to me that there’s mold and other debris in the chip out areas for it to be black.

Clean, sand, grind until fully clear. Wash down with acetone. Repair inside laminate as needed.

When spraying the finish PER Gel coat on, try and color match as best as you can. After apply the gel coat with surfacing agent (liquid wax) added to the gel coat, spray PVA onto the newly coated gel coat and overlapping the repair area as gel coats need zero oxygen to full cure so you can sand and polish it out later on after it fully dries…give it extra time to do so.

#5

I was thinking mildew or mold also ( the black spot). To my knowledge there is zero benefit for a boat maker to use black fiberglass mat or cloth especially since boats are gel coated.

You may want to contact Ranger Boats with the year, model, etc of your dad’s boat to ask them for the mfg brand and color of gel coat used. Brand won’t matter so much, but to get an exact color match Ranger may be able to help you. If not try www.fiberlay.com and look thru their wide assortment of colored gel coats and pigmented dye’s used for tinting gel coat.

Best of luck :slight_smile:

#6

maybe there’s just black pigment in the resin?