Sanding/smoothing deck paint?

25yearslater · Jun 10, 2012

Hi Jonny. From the gelcoat fiasco I learned it's more a matter of how patient is one willing to be. A great deal depends on the depth of the brush marks. The deeper and less patient one is the more course the grit. About a 400 grit would be a good starting point. Leave some of the brush marks visible and continue down with 600, then 800, 1000 and depending on how smooth 1500, 2000, 3000. I started buffing after the 1500 grit. These are ballpark numbers as each person can tailor them to their own liking. Be prepared for the possible breakthrough. If timid start at 600 or 800 and see how it feels. Hope this helps.

catsailor · Jun 10, 2012

JonnyQuest said:
My deck paint from PO was brushed on and has fairly deep brush marks in it making it not so pretty up close. Also tends to trap dirt and grime easily. Paint is not glossy, rather a dull finish. Don't know what type.
I'm thinking of experimenting with sanding the paint a bit to get it smooth and then seeing how it looks. Never done this. Assume I should use an electric sander but what grits? Following that will wax make it shinier without being slippery or would I need some sort of top coat paint to make it look better? Thanks for the ideas here.

I would start following painting threads and tackle it in the spring. Sand it smooth (220-400) and recoat with a better roller/brush. It's not that hard and will last far longer than trying to sand/buff paint, which is not very likely to work (since it has already aged).

25yearslater · Jun 10, 2012

Just a few things remaining Jonny. I'll see what I can do on the walk around. One thing is for sure, I'll be berzerk waiting for next April. I've even got bags of new sails sitting around the house ready to go.

finding41 · Jun 10, 2012

Jonny: I personally would strip the old paint. If it is too thick and has drag (brush) marks it was probably applied in full sun. And if it was applied if full sun the PO either didn't care about the instructions on the can or just didn't follow them. So it was applied wrong. Remove it and do it properly.
On my boat a PO has painted the deck and hull poorly. The paint is coming off both. I am going to strip it this winter and do it properly.
There are some environmentally safer strippers out there. (That sounds wrong.)
Good luck.

catsailor · Jun 10, 2012

finding41 said:
Jonny: I personally would strip the old paint. If it is too thick and has drag (brush) marks it was probably applied in full sun. And if it was applied if full sun the PO either didn't care about the instructions on the can or just didn't follow them. So it was applied wrong. Remove it and do it properly.
On my boat a PO has painted the deck and hull poorly. The paint is coming off both. I am going to strip it this winter and do it properly.
There are some environmentally safer strippers out there. (That sounds wrong.)
Good luck.

Good points.

Re. 2-tone, done with subtle differences, it does help delineate non-skid. My last boat was done that way and I liked it better than my current 1-tone.

Re. Soundness of old paint, I had thought about saying the say thing, but it really varies. My last boat needed repainted only because of wear, and the underlying coats were very sound. I also knew it was Imron. I would look VERY closely for pealing, and when sanding, look for a nice feather. The other thing I might consider is doing a test spot this summer, just to test paint compatibility and to get a feel for the project. Perhaps some high-wear but out of the way area like the bow. You will learn how to get the paint smooth without the performance anxiety.

Which brings us back to the subject of strippers.

finding41 · Jun 10, 2012

Yes chemical stripper. I got a bunch of safe stripper??, (I can't remember the name, It's at the shop, but there are videos on youtube with it.) It's vegetable based. Follow the instructions closely or you get a dry crinkled mess. I use palstic (6mil or contractor garbage bags cut open) to cover the surface of what I have applied the stripper to and let it sit longer to work. I only remove what ever amount of plastic (like 1/2 a garbage bag) I know I can work without the stripper drying out. Then on to the next...
I'll post what the stripper is tomorrow.
Note: All chemical strippers are not good for you. Wear the safety stuff recommended on the can. It is still nasty stuff. Maybe just not as nasty.
(I used to wear glasses until Nov./11. when I had lazer surgery. I originally thought great! No more glasses. I now have about 6 pairs of safety glasses I find myself wearing around all day! But I can wear sun glasses now too!)

Anonymous 121765 · Jun 11, 2012

Jonny,

I did my topsides about 2 years ago. I found a brand of two part called Supermarine. Before you do anything, check out their web site. They have chemical products that may not have you doing alot of sanding.

This paint has been bullitproof for me so far. Here's their link, you can ask them technical questions.

http://supermarinepaint.com/underwater-epoxy-sm-6000.asp

CR

ShulerJ · Jun 11, 2012

The anti skid surfaces on my H33 were shot. We used Kiwi paint available on this site. All we had to do is lightly sand any high spots or flaking areas, wash it, tape the borders and then paint. Kiwi is water based. Very easy to use. We found it worked best with one person applying the paint (with a brush) and the other rolling it (textured roller, comes with the paint). Make sure you pull the tape up as soon as the paint is on. This has been on for two years and shows no signs of wear or any other defect. One gallon did the whole boat.

John

captnron said:
Jonny,

I did my topsides about 2 years ago. I found a brand of two part called Supermarine. Before you do anything, check out their web site. They have chemical products that may not have you doing alot of sanding.

This paint has been bullitproof for me so far. Here's their link, you can ask them technical questions.

http://supermarinepaint.com/underwater-epoxy-sm-6000.asp

CR

Chuckbear · Jun 11, 2012

To give you a little more to consider, here is our non skid replacement, http://trawler-beach-house.blogspot.com/2009/08/transforming-non-skid-decks.html . We love this stuff and are currently doing the non skid on our trawler with it. Chuck

finding41 · Jun 11, 2012

What is happening with peoples non-skid? Is the problem too much paint filling the groves? If that's the problem why not get rid of the paint that's filling the groves? (Chemical stripper and a stiff bristle brush, or power washer.) I strip and paint usually 5 or 6 wooden porches a year. I want as much of the old paint off to insure that I have a good substrate to bond to. I use chemical strippers and follow that by sanding. This gets the wood back as close as I can get it to new.
My point is that if you are going to paint you should prepare the surface as much as possible. Then use an application technique that fits the job. (In this case probably a small foam roller, and more than one coat.) My boat has thick brush marks all over it...So, someone didn't do it right. (I'm pritty sure I haven't seen a paint can that says "just slop it on" on the side.)
I know there are all kinds of different anti-slip products out there. Sure they work when used properly, but who uses them properly? (I have seen someone use beach sand. Don't!) Not the people applying it over an old paint job they personally didn't do or wasn't professionally done. You can't trust the structural integrity of the paint. Your topside flexes and expands and contracts. The more paint you have on it the higher the risk of paint failure.
Here is a picture of paint failure on a 80ish year old wood porch.

Sanding/smoothing deck paint?

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