Vertical gel coat repair

[Arminius]

Repairing the gouge caused by a mooring cover buckle. A clear Mylar sheet from office supply holds hardening gelcoat in place. I am not a fan of You Tube but this guy makes gel coat repairs look easy, definitely a winter project agenda item.

 

[firecadet613]

Spectrum Color Patch Paste will stay without the mylar sheet. Great stuff!

 

[OllieC]

+1 on the Spectrum. Depending on the size of the gouge, you may have to apply a 2nd coat. I enjoy working with the stuff, and almost get instant results that look factory.

 

[Arminius]

Thanks:
This is the paste, $45 plus shipping, shelf life of 6 months:

• Kit includes:
  • 2oz gel coat paste
  • Hardener
  • Easy-to-follow instructions
• Add hardener, mix thoroughly, apply to damaged area using a putty knife
• Perfect for cosmetic repairs: small nicks, scratches, drill holes, worn areas

Patch Paste allows an inexperienced person to make professional gel coat repairs. The paste spreads like vaseline, sets in 5-15 minutes, and is ready to sand and buff in an hour.

 

[Lazy Daze]

I only quickly skipped through the video, but... the mylar is not there to hold the gelcoat - it will stay just fine. The gelcoat is actually holding the mylar in place... to help the gelcoat cure (this kind needs a topcoat of some type to cure out of the presence of air) and also to make a smoother surface (less sanding).

But, like others mentioned, the patch paste is the way to go.

 

[JHornsby3]

You can also get some artic white gel coat and some MEKP. Mix in a small amount of cab-o-sil before your hardener. Fill the spot and give it about 45 minutes and it's ready to sand then finish. Or use the get coat straight by dabbing it into the spot. Wash with acetone and dab more until the spot if filled. Everything should be less than $20. The last gel coat I got was custom mixed for our banana yellow hull. 1 quart of gel, a pint of MEKP and a half pound of cab-o-sil for $10.

 

[Arminius]

Thanks. I went by the boat repair shop with my cellphone image and he included spraying in his estimate. The UTube repair seemed to indicate I could get a glossy finish with 900 or so wet paper and wax. Is any spraying required?

 

[firecadet613]

Thanks. I went by the boat repair shop with my cellphone image and he included spraying in his estimate. The UTube repair seemed to indicate I could get a glossy finish with 900 or so wet paper and wax. Is any spraying required?
View attachment 112167

No need to spray. Hit it with acetone first, mix up the Spectrum Color, put it on, let it cure, wet sand then polish.

 

[Arminius]

Looks much easier than auto body as no spraying involved. Clear he was just jacking up price. I'll see about getting a custom paste mix. Still intend to get a Mylar sheet as watching a patch bulge and sag like the hardened UTube examples would be undesirable. Question: Do you see any need for Bondo type filler on this deep gouge?

 

[firecadet613]

Looks much easier than auto body as no spraying involved. Clear he was just jacking up price. I'll see about getting a custom paste mix. Still intend to get a Mylar sheet as watching a patch bulge and sag like the hardened UTube examples would be undesirable. Question: Do you see any need for Bondo type filler on this deep gouge?

From the picture it looks like it's just through gelcoat, no fiberglass, so IMO, no need.

*Edited to add (based on Lazy Daze response below), I've never covered the Spectrum Patch Paste. I had to buy a quart of red on a previous boat (they didn't make the patch paste in that color), and since I had to spray that on, I did spray with PVA over it to help it cure.

Patch Paste is some great stuff - I've used it on every boat I've purchased to patch up little nicks, etc. from previous owners.

 

[Lazy Daze]

Looks much easier than auto body as no spraying involved. Clear he was just jacking up price. I'll see about getting a custom paste mix. Still intend to get a Mylar sheet as watching a patch bulge and sag like the hardened UTube examples would be undesirable. Question: Do you see any need for Bondo type filler on this deep gouge?

I saw that part in the video where he used the putty knife to smear the gelcoat in... it bulged out because of the way he did it - he left an air bubble in there.

I've never covered the Spectrum patch paste - will it cure with the mylar on there? You should check into that. But, you really don't need it.

Like Fire said, I don't think you need filler - it's probably right on the edge of how thick I'd go with just gelcoat - but that's a flat spot, which helps.

 

[OllieC]

Be sure to masking tape off the area around the spot your are going to repair, otherwise you'll be sanding off gel coat where it's not needed.

As far as wet sanding, I've started with 600 to shape it, then 900-1000 (can't remember it was in a mixed pack) to smooth it out, 3m Finesse to brighten it because the finish will be dull, and then a wax.

Lazy did mention something of importance and that is potential bubbles, which may require multiple coats or layers if you're a perfectionist like myself. Also, you can get tiny bubbles if you add too much hardener, so follow the directions.

Spectrum may have your exact color pre-made as they do for my 2005.

 

[JohnnyAlpha]

Polyester resin and polyester gelcoat needs to be in the absence of oxygen to fully cure. There are a few ways this is usually accomplished the simplest is to use a wax additive or buy waxed gelcoat. During the curing process the wax additive will float to the top cutting off the oxygen. The Spectrum paste is likely waxed gelcoat thickened with fumed silica (cabosil) so you would just need to add the appropriate amount of mekp for the temperature and apply. If you need to apply multiple coats to fill low spots all the wax must be removed by cleaning well with acetone and sanding. In my opinion repairs and blending in gelcoat is much easier than automotive paint.

 

[JHornsby3]

I have always just used the gel coat and not used the wax. Well, if the temps were lower I would add a drop or so. But I have always made sure the repair or gel coat was taller than needed. Then just cleaned with new clean acetone. Only needed the wax in winter when the temps got below 40*. Or waited a very long time for it to not be so tacky.

But like a glue thread on a wood workers forum, there is a million ways to do it.

 

[Arminius]

Thank you for the excellent advice. I ordered the Spectrum paste in the exact color of my boat (Pearl Ash LE) and will eventually post an image of the finished product. I've gotten good results with Bondo so I'm pretty confident. Masking off my work area is a good idea. Kit includes hardener and instructions which I will follow. $45 rather than the $550 the shop bid! Glad I made the initial post as I was on the wrong track with the amazing mylar sheet.

 

[JohnnyAlpha]

Temperature would have an effect on the amount of catalyst you would need though 40° is awfully cold to be working with this stuff. You still would need to block oxygen in order for the gel to fully cure. Thicker applications can cure internally but the surface generally won’t achieve a full cure. It’s easy enough to add Wax or another additive like Duratec, or to cover the area with pva to achieve the best results and performance of the repair.

 

[JHornsby3]

We would lay up control surface tips at colder. Sometimes they would have to sit out overnight and sometimes there would be room in the oven.

Wax also doesn't play too nice with 80+ % humidity. And that is why I almost never use it. I have seen the wax just sit on top and never mix in. I'm not saying to never use it, or that I haven't. I just don't use it very much.

 

[Arminius]

Spectrum is great stuff and I appreciate the good advice. The auto parts store sold wet or dry attached to sponge blocks which were very effective sanding blocks. Disposable spatulas avoided contamination and provided a good edge. Got a good result on first try below the disturbed area highlighted by the flash.