what grit sandpaper to strip boat paint ?

[rfuerst911sc]

I'm starting the restoration of my 13 1/2 ' Boston Whaler. Interior is completely stripped out and the outboard has been pulled. She has previously been painted inside and out with who knows what kind of paint. The interior is all checked/crazed so it needs to all be removed. So for the majority of the flat surfaces I'm going to use my air driven DA sander, a Makita electric palm sander and a Dremel multi tool with that triangular sanding attachment. So for those of you that have done similiar work what grit sandpaper should I start with. I want to get it done as quickly as possible but of course don't want to damage the glass/gelcoat. I'm guessing 40-50 grit but would like to hear what others have done. I'm guessing some of the checking/crazing is probably in the gelcoat also so it may be more than just paint removal. Any advice is appreciated.

[TimT]

I think 40-50 might be to aggressive, you can always try in an inconspicuous area to test...

I would start with 80...

Do you have a pressure washer? you may be able to get under it and blast some of the paint off....

[rfuerst911sc]

I don't have a pressure washer. Now that I think about it I have some 80 grit disc's hanging on the wall I'll give them a try. Thanks

[nota]

try paint remover first
small area and remove quick before it eats into the gelcoat
sanding fiberglass is why we have Haitian's here

get real first quality gear to protect yourself inc throwaway suits
tape sleeves and cuffs

use a shop vac next to the sander

DONOT try to remove all the gel-coat
or re-gel-coat as it will not cure in air
just fill cracks and repaint

[Zeke]

Sandpaper is a bigger subject than most people think it is. I would try to remove the paint w/o getting into the gel coat too much. This could be a remover of some sort, you have to experiment. Maybe a heat gun will get a lot of the paint off. I know gel coat will take quite a bit of heat before it bubbles.

After that go with the finer paper that works. 50 is rough. I do use a lot of 80 to begin with and I buy the D weight good stuff for my orbital (not random) Makita 1/4 sheet sander.

[DanielDudley]

Heat gun is a good call, if you have the touch. You just want to get the paint warm enough to scrape with a dull scraper. Get the bulk, then switch to fine sanding.

[rfuerst911sc]

Do you guys think the citrus based paint strippers might do the trick ? The only paint stripper I've ever used was the aerosol aircraft stripper on some Fuchs wheels and that stuff was nasty. I'll go ahead with my DA sander and test some flat spots with the sandpaper I have and see what happens. Thanks guys.

[drcoastline]

Don not use sand paper at all to remove the paint. You will damage the gel coat and then you will have to go back and repair the gel coat in order to move forward. You will also remove all the non-skid. I beleiev on a 14' whaler the non-skid is a diamond pattern in the gelcoat that will be removed by sanding.


Citrus stripper and aircraft stripper will work just fine. They say not to use on fiberglass but I have used both extensively to remove paint from fiberglass with out any negative effects. Brush the strippers on then cover with biz queen (plastic drop cloth) to keep from drying out. lets stit for 20-30 minutes. You should be able to blow the loosened paint off with a garden hose on stream. You may need to redo this process several times depending on the amount of paint. For nooks and cranies put some stripper on cover for 15 minutes. you can then use a plastic paint scrapper and a red or green 3M pad to scrub. Do not use a metal scraper you will gouge the gel coat. Do not use steel wool it will come apart and leave little pieces that will rust causing major agravation. If you have a wood shop near by go and ask if you can have their shavings they work great as a non damaging abrasive and the paint and stripper absorb and stick to the shavings making claen up easy.

There is a stripper called peel away that you could also buy. Similar process as I describedbut at 3X the price. When the stripper dries it sticks to a paper cover and peels off. There are other strippers as well inter strip (marine grade) about $30.00 per quart.

When you get all the paint off . Neutralise with soap and water. Then go back and wipe down with MEK and a green 3M pad. You will be surprised by the amount of reside left on the surface you can not see.

You may also want to vist jamestown distributors dot com for supplies. There are also a ton of DIY videos on the site. Classic sea craft dot com and classic boston whaler dot com are the pelican counter parts for these two classic boats.

Good luck with your project.

But most importnantly do not sand.

Oh yeah, and DO NOT put any rags or wood shavings with stripper or solvents in a can or box or can for disposal while wet they will spontaneously combust.

[David McLaughlin]

I wouldn't use anything more course than 180 grit. Even that you need to be careful not to damage the fiberglass. A DA will rip that old paint off quite quickly.

[JeremyD]

Interlux makes a stripper for paint that will not harm fiberglass.

This website has some excellent references for boston whalers

Classic Whaler: Boston Whaler: Reference: Frequently Asked Questions

13' whaler is a great restoration project...

[rfuerst911sc]

Great tips guys thanks. My worry with the strippers is the ambient temp's now that we're into winter. It is still in the 50's here during the day so maybe that won't affect the performance of the strippers. I'll try some and see what happens. Thanks again.

[drcoastline]

rfuest911sc,

The cooler temp actually helps because the stripper won't dry out as quickly. That is why you cover the area with plastic sheeting.

After you paint on the stripper. Don't brush the stripper back and forth that makes it dry out quicker. Just apply in one maybe two strokes to cover the surface then lay the plastic over the area and press it onto the stripper. It keeps the stripper from drying out and allows it to work longer. 15-20 minutes usually will allow the stripper to work but you may find it takes a little more or less time. Experiment with times to find what works.

[Hard-Deck]

80, don't touch gel coat