We need to grind down the cockpit coaming and paint it.

capta

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Jun 4, 2009
4,766
Pearson 530 Admiralty Bay, Bequia SVG
We do not need to save the nonskid, but there are a lot of holes from the teak that we will fill.
What type of sander would you recommend?


coaming cracks2 sm.jpg
coaming cracks sm.jpg
 
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Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
A random orbit or a dual action sander with 40 grit paper will make short work of this and make it more difficult to gouge the underlying laminate. If you're really careful, an angle grinder with a flapper disk will be even faster with a higher a risk of damage to the glass. Finish up with some 80 grit at the end.

There are now sanding screens available in some places that fit on standard 5 or 6 inch sanders. These don't seem to clog as fast, although I haven't tried them.
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
40 grit scares me. It can make deep scratches that are tough to remove without going further than wanted. I'd start with 60 grit, or switch to 60 as sson as the non-skid looks thin.
I'm guessing @capta is going to replace the nonskid with something else. While prepping for the paint the scratches will be removed. And the nonskid hides a lot of sins, like sand paint on a ceiling.
 

capta

.
Jun 4, 2009
4,766
Pearson 530 Admiralty Bay, Bequia SVG
I'm guessing @capta is going to replace the nonskid with something else. While prepping for the paint the scratches will be removed. And the nonskid hides a lot of sins, like sand paint on a ceiling.
Nope, don't need non-skid there. Nobody can walk there. Just want to clean up the surface, fill the holes and paint it.
 
Mar 26, 2011
3,401
Corsair F-24 MK I Deale, MD
I'm guessing @capta is going to replace the nonskid with something else. While prepping for the paint the scratches will be removed. And the nonskid hides a lot of sins, like sand paint on a ceiling.
Yeah, unless you want those cracks coming right through the new paint, you're going to grind deep and then do some manner of filler or high build primer before paint, with more sanding and perhaps even a layer of finish cloth and more sanding. Hard to say. But you are going to sand into the first layer of laminate.

I would not use a disk sander. Too much chance of gouging. 60 grit might be a good compromise. And some papers cut much faster than others; 3M purple is the best value when endurance and speed are included.

And you probably want new non-skid; falling down is bad.:(
 
Sep 22, 2018
1,869
Hunter 216 Kingston
What type of sander would you recommend?
I would NEVER try to talk someone out of buying a power tool ;) but you could make a simple sanding bar. Buy some rolls of sandpaper and a piece of wood same width. Length should be at least a few feet long. Put on a couple of stand-off blocks and a handle and the tool is made. Staple the sandpaper onto the board and sand away. OH yeh stop at the beer store for fuel! :)
 
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
I would NEVER try to talk someone out of buying a power tool ;) but you could make a simple sanding bar. Buy some rolls of sandpaper and a piece of wood same width. Length should be at least a few feet long. Put on a couple of stand-off blocks and a handle and the tool is made. Staple the sandpaper onto the board and sand away. OH yeh stop at the beer store for fuel! :)
:thumbsdown: sounds like too much work. :huh:
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
There are now sanding screens available in some places that fit on standard 5 or 6 inch sanders. These don't seem to clog as fast, although I haven't tried them.
I haven’t tried them on gelcoat but for antifouling the screens definitely do work better and longer than paper.
 
Mar 26, 2011
3,401
Corsair F-24 MK I Deale, MD
I haven’t tried them on gelcoat but for antifouling the screens definitely do work better and longer than paper.
What screen did you use? The ones I tried were not as good as 3M Purple. They didn't clog and the vacuum worked well, but they didn't cut as fast or last as long. But the idea makes sense, just as it does for drywall.
 

capta

.
Jun 4, 2009
4,766
Pearson 530 Admiralty Bay, Bequia SVG
Ho boy. Once again, this is the cockpit coaming that the winches sit on. Nobody is ever going to walk there, just rest their elbows there, hense no nonskid.
I didn't ask for a method of dealing with the cracks. They were caused by years and years of wood soaking up water, swelling, then heating up or freezing and drying out, moving the screws. We have no other cracks like this anywhere on the boat.
I appreciate the idea of the wood, but I've got to cut too deeply and I don't have the time or space.
Since sanders here are very expensive, never mind the discs, I just wanted recommendations on sander types.
 
Aug 12, 2020
53
Lancer 36 Pago Pago
4" angle grinder with a flap disc, keep it moving so the structure does not overheat.
 
Sep 22, 2018
1,869
Hunter 216 Kingston
I just wanted recommendations on sander types.
I use a Dewalt model D26441 - 1/4 sheet palm sander that doesn’t require any special discs etc. Take normal sand paper sheets cut them up for size and sand away. Dust bag comes off if space is tight.

1FAEB61A-B022-4581-B4CE-2706C66D041A.jpeg
 
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Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
I use a Bosch ROS20VSK Random Orbit sander.
This is the corded version. They may make a cordless model.

I have an attachment to connect to a vacuum with a bag filter to capture the dust. It is easy to use. You can quick change sanding pads. The grit determines the aggressiveness used to remover product. 80 grit quickly. Removed the molded nonskid on my bow so that I could install the windlass. I followed up with less aggressive sanding of the area with the change of a pad and some gelcoat.



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Jan 19, 2010
1,169
Catalina 34 Casco Bay
BEFORE you get caught up in a surface repair, have someone conduct a moisture test. If you have moisture in the core and seal off the surface, you'll compound the problem.. Sometimes the fix can be done from below by cutting out the bottom of the cockpit sole and repairing. Then the cockpit is intact albeit with glass crazing..but then there's Awlgrip....
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
What screen did you use? The ones I tried were not as good as 3M Purple. They didn't clog and the vacuum worked well, but they didn't cut as fast or last as long. But the idea makes sense, just as it does for drywall.
Mine were Mirka Abranet HD or Abranet Ace HD (I have one of each in my spare pile; not sure which worked better). Seemed to cut at least as well as whatever ordinary paper I used to use, and lasted probably more than three times as long.

(With apologies for the thread drift)