First time gelcoting and its a big one

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NickCawks

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Hello all! I come today with a question... or maybe more so I come in search of opinions.

I am currently working on a 95 XP720 semi-resto project, nearing the end of it, I have obviously saved the best for last.

After about a month of procrastination, I have finally flipped the ski over to begin attempting to re gelcote the hull. I have been putting this off because I am a mechanic, not a painter and this prospect makes me somewhat nervous. This is amplified by the fact that I have quite a large area to do and compounded by the previous owner's work.

At some point, this ski hit something hard and had a pretty decent sized hole, as well as the surrounding area suffering some damage, and has extensive areas where gelcoat the has been stripped away. It appears to me that the previous owner took the ski to someone who knew what they were doing with the fiber glass. The repair seems to have been executed very well and looks like it did a good job of maintaing the structural integrity of the hull.

After this repair was done, I can only guess that the previous owner said something like "No you don't need to paint it I can do that", then proceded to actually paint the hull.

hull edit.jpg

My question is mostly related to prep, I have put several hours into researching through the actual process of applying the gelcote and have all that worked out. I am just not sure where I need to start with prep / how in depth the prep needs to be. Looking at the ski it feels like I should just go ahead and do the entire hull, but is that going to be unneeded work?

Obviously I need to sand it, but how far do I sand?
-Do i just need to sand the peaks down where the chips begin?
-What grit(s) should I be using?

In lieu of trying to answer my jumbled mess of rambling questions -
If this ski was flipped over in front of you, what would your plan of attack be?

I have scowered the forums and internet in search of someone giving a clear answer to my questions, but it seems that everything I find is pertaining to a MUCH smaller area and mostly is chip repairs. I know the subject has been beat to death on this forum, but I just didnt feel that I am prepared enough for my specific situation to jump into it.

As always, any help is greatly appreciated
Thanks,
Nick

To mods: I am sorry if this turns out to be a duplicate posting. I have tried twice to submit it and it just brings me back to the 2-Stroke Sea-Doo PWC forum and my post is not showing up on it or inside my recent activity.
 
Unfortunately whoever repaired it before didn't prep it correctly which is why the paint is chipping off. If it was mine, I would strip all the paint and primer from the previous repair and spray with a good primer surfacer before spraying gel coat.
 
I took on a first time gelcoat repair and wrote it up here: “Gelcoat with a PreVal sprayer”.

I am helping a friend now that has significant cracking all over the upper body of an older ski he picked up. He had to grind out every crack down to base glass and is at the fairing stage now.

Here are a few things. If the yellow is really paint and not gelcoat, strip it off as suggested by jts32. Any of those gouges that have sharp edges need to be ground out and filled with a fairing compound. The repair area looks like paint over glass. When finished correctly, you should not see it at all. Sand it down and fair that also. I went down to 120 grit, but I am aware that others have used even more coarse sandpaper. You can gelcoat over 180/200 grit scratches. You need laminating gelcoat and PVA on the final coat.

Brushable gelcoat is available, but I have not used it. If you gelcoat, you will need to sand up to 1500 wet, then polish out. If you use Awlgrip or equivalent, you will not need to sand it out. Because it is the bottom, I might be inclined to paint it. You must prep accordingly, or it will peel again.

I found this sounds much more daunting than it really is. Just takes time.
 
Unfortunately whoever repaired it before didn't prep it correctly which is why the paint is chipping off. If it was mine, I would strip all the paint and primer from the previous repair and spray with a good primer surfacer before spraying gel coat.

Just to clarify, when you say strip it you mean sand it down to the fiberglass?

Brushable gel coat is available, but I have not used it. If you gelcoat.

I already purchased (https://www.gelcote.com/product/1995-sea-doo-yellow/) from Gelcote international. I guess I probably should have already mentioned that. On the bottle, it says it can be sprayed or brushed.

I do not have a spray gun or a compressor and have been planning to "brush" it on, but actually found some information on using a roller which I think is what im going to try.


If it were mine..................I'd get another hull. honestly if you had to drive 8 hours round trip you'll still save HOURS on the repair work. You'll be ahead of the game. I really wouldn't waste time fixing it.

I wish I could. I am well above topped out on my budget for this thing and just can't spend any more money. I do however have a good bit of free time and don't mind doing the work, but want to make sure I have the full picture before I start.
 
With regard to the paint, if it is a rattle can lacquer or enamel, you can strip it. If it is epoxy based and chipping, I would sand it. Get yourself really old clothes or a non-woven painting cover up. You need a respirator because the dust goes everywhere. You need to get to a stable surface before you start building it back up. If that means bare glass, that is what you will need to do. As racerxxx says, it will take HOURS! Do not rush it. If you don’t have a stable surface, the new surface will just come right off.

Gelcote International is the right place, Gabriel is the guy behind the scenes and knows his stuff. I’d like to hear your experience on brushing/rolling. Seems rolling would introduce air and results in pin holes, but let us know.

Good luck.
 
I’d like to hear your experience on brushing/rolling. Seems rolling would introduce air and results in pin holes, but let us know.

Good luck.

Yeah I am interested myself in seeing how it works. Here is a link to a video with someone explaing using this technique. It looks like a viable option, but he is just painting a flat surface in the video so I am sure there will be some unseen difficulties when doing the ski.
 
I put a lot of thought into my plan last night. Considering what you all have told me I believe this will be my order of operations.

1- attempt to strip as much of the paint and primer as I can with some paint stripper.

2- In the affected area, sand the paint and primer off to the bare fiberglass.

3- Sand the raised ridges of gelcote that surround the area to create more of a slope than a drop off (in an attempt to avoid any lines showing up through the finished product).

4- Apply gelcote.

5- high grit sand and buff to a nice even gloss.

Any step you guys can think of that I am missing?

Sidenote: When I get done with step 3 I will post a picture and see if you guys think I am ready to move on.

UPDATE: I went ahead and sprayed some paint remover on it which worked very effectively. To my surprise after wiping away the grey primer I found the original layer of gelcote.
20171120_092846.jpg
I decided to stop on the left side there because I was concerned about the idea of putting the paint stripper directly on the fiber/resin.
Did some test sanding over there on the right side and I'm feeling pretty good about it.
 
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Just finished up my first 2-hour sanding session. Went until my back couldn't handle leaning over the ski anymore.

I am feeling fairly optimistic, things seem to be better underneath then they first appeared. I would say another couple hours of sanding and I will be ready to move on to the next step.

20171120_125439.jpg
20171120_125448.jpg

I was glad to see that the original gelcote was largely intact. In my mind, this means I do not need to sand down to the glass to know I have a good bond.

I plan to continue sanding in the current grit tomorrow a bit more, then moving up to a higher grit before applying gelcote. However, things are surprisingly smooth already considering I have been using a 100 grit.
 
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Already looking better. All those scratches and gouges need to be opened up in order to take the fairing compound. Nothing less than say 1/4” wide with smooth sides. No sharp edges.

What condition are the sides of the hull up to the rubrail? That also needs to be sanded in order to take new gelcoat, but if they are in good condition, just a 180 grit scratch pattern is all you would need.
 
Already looking better. All those scratches and gouges need to be opened up in order to take the fairing compound. Nothing less than say 1/4” wide with smooth sides. No sharp edges.

What condition are the sides of the hull up to the rubrail? That also needs to be sanded in order to take new gelcoat, but if they are in good condition, just a 180 grit scratch pattern is all you would need.

Yeah I have kind of been ignoring all the gouges at the moment, but of course I will need to deal with them before applying the gelcote.

the sides of the ski are actually in pretty good condition. I think a light sanding will take care of them. Especially the areas that are still covered in the SeaDoo stickers. I know there is some nice gloss under there :D. I will be taking those off in the next couple of days.
 
Following for info!

Will you be doing a color change?

Sanding is a royal pain for sure, are you doing all that sanding by hand? HF has a cheapo wet sander unit that actually works pretty well.
 
Will you be doing a color change?

No, I was actually thinking about this earlier while sanding and in retrospect, I really wish I had picked a different color. At the time I had not flipped the ski and the majority of the damage was resting on the trailer so I couldn't see it.

Due to this, I thought I needed to cover somewhere around a square foot section rather than pretty much needing to redo the whole thing and just went ahead and ordered the yellow. I could still probably get a refund and change it as I have no opened the bottle I ordered, but the shipping took like 2 weeks the first time.

Sanding is a royal pain for sure, are you doing all that sanding by hand? HF has a cheapo wet sander unit that actually works pretty well.

I really considered buying a wet sander, but I just don't have any budget left at the moment and it's a tool I don't really need otherwise.

I have just been cranking away with a Ryobi dry palm sander. It's getting the job done well enough. I notice that the sandpaper doesn't really hold on to the gelcote very much (at least the lower grit), so thankfully I'm not blowing through sandpaper.
 
To fix the chips and gouges, just feather the gel coat back until they are gone. If the gouge goes into the fiberglass and can't be removed by just sanding the gel coat, apply a thin coat of polyester finishing putty and sand smooth. I have 20+ years of auto body experience and prefer the Evercoat Metal Glaze putty. It sticks to metal, fiberglass, SMC, and sanded paint. We use it on almost every repair job. Im unfamiliar with fairing compound, but there is no need to open up the scratches with the polyester putty.
 
Does the Metal Glaze absorb water like Bondo does? If so don’t use it on watercraft.
 
Does the Metal Glaze absorb water like Bondo does? If so don’t use it on watercraft.
I always believed glazes we're waterproof, but didn't see it anywhere on the container, so I called a supply rep friend to ask. He said it isn't labeled as waterproof, but the make-up and resins in the glaze won't absorb water like a regular filler. However it should only be used as a skim coat to fill scratches and chips. Repairs that require thickness and build up of material should be done with a product like Everglass and can be top coated with the glaze to fill pinholes and sand scratches
 
To fix the chips and gouges, just feather the gel coat back until they are gone. If the gouge goes into the fiberglass and can't be removed by just sanding the gel coat, apply a thin coat of polyester finishing putty and sand smooth.

I have found that probably 90% of the gouges I have are sanding away, and only a few of them are into the fiberglass. It's pretty obvious that not only was this thing parked on beaches, that might have been the only place it was ever parked beacuse the keel is a mess.

I will probably just stick to using the fairing compound because it is what I already have. I would definitely be interested in seeing someone do a repair using the finishing putty, to get an idea of what the process is like. It would also be cool to see someone do a repair then show us how it held up after a season.

That said I appreciate the suggestion, as always I am thankful for any input!

Add some flake to that yellow

Keep up the solid work!!

Haha, I might. Some purple fleck would look pretty cool in there :D
 
I found the chemistry of fillers also to be a little confusing. I have a friend that restores old boats. He gave me the following guidelines:
Above the waterline- Polyester(Bondo, etc), Vinylester (3M Marine Filler) or Epoxy based fillers(Total Boat or West). Below the waterline-Epoxy based fillers only.

So, I don’t know about water absorption, but this guy has been restoring boats for years, so I follow his advice.

Sorry, but that’s the sum total of my knowledge on that subject. Maybe another forum member can get into the why’s and wherefor’s.
 
Sorry, but that’s the sum total of my knowledge on that subject. Maybe another forum member can get into the why’s and wherefor’s.

Hey its information, we accept all forms here :)



Quick Update:
The weather has turned on me today. Supposedly going to be raining till late afternoon (They are always wrong though). I refuse to do the sanding in my garage, so the project is postponed until the rain lets up :(. Hopefully, the weather changes and I can get out there this afternoon as today was the only FULL day I had opened to work.
 
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Hey its information, we accept all forms here :)



Quick Update:
The weather has turned on me today. Supposedly going to be raining till late afternoon (They are always wrong though). I refuse to do the sanding in my garage, so the project is postponed until the rain lets up :(. Hopefully, the weather changes and I can get out there this afternoon as today was the only FULL day I had opened to work.

So what kind/brand fairing compound did you end up using to build up/fill the gouges and deeper marks?
 
I originally had something on hold for me at a local store called the "West System". I just gave them another call and spoke to a different person who told me that I cannot use the fairing compound without buying the rest of the system which also includes resin and a harderner.

I really don't want to spend the money on the entire system so I told him to just cancel the order and now I actually need to figure out what to use.

Does anyone have any suggestions?
 
I found the chemistry of fillers also to be a little confusing. I have a friend that restores old boats. He gave me the following guidelines:
Above the waterline- Polyester(Bondo, etc), Vinylester (3M Marine Filler) or Epoxy based fillers(Total Boat or West). Below the waterline-Epoxy based fillers only.

So, I don’t know about water absorption, but this guy has been restoring boats for years, so I follow his advice.

Sorry, but that’s the sum total of my knowledge on that subject. Maybe another forum member can get into the why’s and wherefor’s.

Well, I would trust Dave's source over mine. In my mind, someone giving advice with real world hands on experience trumps advice from someone reading it off of a material data sheet.

I have a GTi hull with bottom damage that I was going to scrap. Maybe I will use it as a Guinea pig to test a few products and their durability.
 
I originally had something on hold for me at a local store called the "West System". I just gave them another call and spoke to a different person who told me that I cannot use the fairing compound without buying the rest of the system which also includes resin and a harderner.

I really don't want to spend the money on the entire system so I told him to just cancel the order and now I actually need to figure out what to use.

Does anyone have any suggestions?

This is what was recommended to me but I haven't started on it yet. I have a similar condition hull I will be spending time on soon. Lots of small cracks, chips and a few impact areas where glass is exposed. My plan was very similar...sand it down, grind out the cracked areas, grind down edges on gouges to feather them out a bit then acetone wipe and fill with

https://www.westmarine.com/buy/ever...MIpuOa3KPQ1wIVAQxpCh10-A4JEAQYBSABEgIn8fD_BwE
 
I originally had something on hold for me at a local store called the "West System". I just gave them another call and spoke to a different person who told me that I cannot use the fairing compound without buying the rest of the system which also includes resin and a harderner.

I really don't want to spend the money on the entire system so I told him to just cancel the order and now I actually need to figure out what to use.

Does anyone have any suggestions?

Yes. The West System Epoxy has resin, hardener and a filler (like cabosil) to make the paste.

You can buy the Total Boat Epoxy Fairing Compound from Jamestown Distributors. It is a 2 part Epoxy Filler.
https://www.jamestowndistributors.com/mobileportal/show_product.do?pid=97775
 
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