Fiberglass hull paint prep - simulated plank joint grooves

[GREZ]

For my 34' Marine Trader, I am having the hull painted by a professional, but am doing the prep myself. A PO had applied a clear coat that is flaking badly in places, and totally gone in some other places. My job is to sand the remaining clear coat off, down to the 'paint'. The hull is fiberglass, with the little horizontal grooves to simulate wood plank joints, and the clear coat is perfect in those grooves.
Question is... what is the efficient, effective method to remove that clear coat? A special tool perhaps? My elbow? Chemicals? If you have 'been there' any experience or advice is most welcome. And as always, Thank You!!
Grez

 

[READY]

I would experiment with some strippers. Perhaps one of the citrus based ones to start? Does Acetone do anything? It would be painstaking at best the completely sand those grooves.

 

[DDW]

Another possibility might be a Fein type oscillating sander. The Fein comes with a sanding block attachment with tight radius, about what would fit in those grooves. Could be modified to fit exactly it is was off too much. If the clear coat was P.U. like Awlgrip, then almost no chemical will touch it.

Still going to take awhile - I don't envy you the job.

 

[Comodave]

I would try to find a tool that is about the width of the grooves and try to scrape them out.

 

[Southern Boater]

For my 34' Marine Trader, I am having the hull painted by a professional, but am doing the prep myself. A PO had applied a clear coat that is flaking badly in places, and totally gone in some other places. My job is to sand the remaining clear coat off, down to the 'paint'. The hull is fiberglass, with the little horizontal grooves to simulate wood plank joints, and the clear coat is perfect in those grooves.
Question is... what is the efficient, effective method to remove that clear coat? A special tool perhaps? My elbow? Chemicals? If you have 'been there' any experience or advice is most welcome. And as always, Thank You!!
Grez

Sounds like the PO put the horrible PoliGlo on the hull. Sand it with 120 grit, you will spend way too much time and money with so called “strippers” and the surface will still need the 120 prep for the primer coats anyway

 

[Comodave]

Poliglo does make a stripper for it I believe. Don’t know if it works or not.

 

[Bmarler]

Plank lines are a pain in the rear, that’s for sure. There are sander attachments for oscillating tools, and there’s a tool by porter cable called a profile sander that have the right shape tote in there, but I actually prefer to use hand sanding blocks. I have a bunch of different shapes of these by dura block. Mostly I use them for car restoration projects, but they work the same on boats.

Amazon.com

Use self adhesive paper on them. I use a fairly coarse grit for plank grooves. You want the surface to have some tooth so it holds the paint instead of letting it run out the bottom.
You may be surprised how fast you can work your way down a plank line with an eleven inch sanding block.

 

[Southern Boater]

Poliglo does make a stripper for it I believe. Don’t know if it works or not.

Apparently not for total removal, mine was old and required sanding. The only good things you hear about it is from the retailers who sell it.

 

[fgarriso]

I had a boat with the simulation wood groves. When we painted it we had to use a soft sanding block by hand. It wasn't that bad.

 

[Comodave]

They say Poli Strip will remove it but I have never tried it.

 

[Snapdragon III]

The radius might be too big depending on the size of the grooves, but I really like these foam sanding blocks for hand sanding into corners. This is the first thing I would try. If you need something with a smaller radius I would try and make my own block out of wood or rubber, and use adhesive backed paper with it. Someday I will be doing this same job on my own boat, so I would be curious what you find that works well.

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[Snapdragon III]

I have one other idea that might work, especially if the clear coat isn't adhered very well. You might be able to scrape it out with a Bahco carbide scraper. (These are an amazing tool to have on your boat in general). They sell round blades for them but ther radius is likely too big. You could get a carbide grinding wheel and grind the tips of the triangular blade to the proper radius, then gently scrape the clear coat out of the grooves.

 

[Datenight]

Plank lines are a pain in the rear, that’s for sure. There are sander attachments for oscillating tools, and there’s a tool by porter cable called a profile sander that have the right shape tote in there, but I actually prefer to use hand sanding blocks. I have a bunch of different shapes of these by dura block. Mostly I use them for car restoration projects, but they work the same on boats.

Amazon.com

Use self adhesive paper on them. I use a fairly coarse grit for plank grooves. You want the surface to have some tooth so it holds the paint instead of letting it run out the bottom.
You may be surprised how fast you can work your way down a plank line with an eleven inch sanding block.

Grez, where are you? I have a Porter Cable profile sander I have never used if you are interested. However I think Bmarier's idea of using a soft block and doing it by hand will be faster and much less chance of an oops. Just change the paper often. You may be able to shape foam sanding blocks to just the right profile if you can not find a commercially available one.

Rob