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gypsie
06-18-2018, 02:01 AM
I'm planning to take my boat out to redo the deck.
37ft Tasman seabird, 1962.
While she's out i am considering taking off all the bottom and topsides paint, back to bare timber and redoing. I trawled the search looking for 'paint' threads but i can't spot one that's relevant.

Hull, 1.25" douglas fir, over spotted gum frames.

Just got some advice from a good paint shop, who called people to find the best solution, but i'm not sold.
The are recommending I Norseal (CPES) the boat first, then apply a 2 pack Norglass product - Ship Shape undercoat, which I have used and it is hard, for both topsides and bottom. Then norglass Weatherfast enamel for top and antifoul paint as usual on the bottom.

My thinking is this system sounds alarming, putting an epoxy type product on the outside only.... And a hard system won't fare well in a flexible, traditionally built woodenboat.

This is an Australian problem, so brand names may vary.
But all thoughts are welcome.

Note - looking for advice for hull, primer, undercoat, top coat.

Also, there's a guy who comes round to the yard with a sand blaster. i was thinking of looking into crushed walnut shells spray to get the paint off. cost a little, but 2 hours work and done.
And, thoughts on fillers etc.. local fisherman who retired from his 100year old DF boat swears by automobile 2 pack filler...huh? worked for him.

Paul G.
06-18-2018, 04:44 AM
37 feet, you'd be surprised how quickly you can do it with a disc grinder, heat gun and scraper. Does it need it would be a question, a good coating well stuck is often best left alone. But lets say you do strip it, no real advantage in epoxy type coatinga especially if it needs to take up seams etc. Just grey primer, marine quality undercoat and enamel, I like international paints. You get what you pay for in paint world.

nedL
06-18-2018, 06:53 AM
Whenever someone talks of media blasting the paint off a wooden boat I have visions of two poor dorys Mystic Seaport paid a ‘professional’ company to media blast the paint off of. The company came in, draped off the area, wouldn’t let anyone see what they were doing, and when finished said ‘all done’. I know the job can be done well, but sometimes ‘after the fact’ is too late to learn otherwise

As for finish products, I too prefer single part oil base enamels. Not as hard and durable finish that will require recoating sooner, but I think future work is easier (sanding, taking care of scuffs, scrapes etc), and it moves a bit more over seams. This may be prejudicial because it is all I have used, and it is just my .002.

David G
06-18-2018, 07:55 AM
I agree that wooding the boat is only done if there's good reason.

If you do - I wouldn't argue strenuously against CPES... but neither do I see it as important. I hate that smell, and would only consider it if there's a very good reason.

I cringe when I hear people talking about applying epoxy on traditionally built hulls. From what you've said so far, I absolutely wouldn't do it.

Don't know what brands of paint are available to you locally.... but I would certainly pick a line of products from one manufacturer which are designed to work together. Except that bottom paints stand alone, and I rely on local knowledge to choose the one that performs best in your conditions. If your local chandlery doesn't have a paint expert - Pettit or Interlux or whoever have tech support lines to help you specify the products. Good luck!

johngsandusky
06-18-2018, 08:19 AM
I recently stripped much of Wandering Star's bottom, 39' strip planked cedar. I had a guy in to test a patch of soda or shell blast (I don't remember which). The paint was harder than the cedar, so it didn't work. He only tested a spot as big as my hand. I used heat and scrapers, both from a heat gun and infrared. A powerful sander would have been quicker, but requires more caution, and creates lots of vile dust in spite of the vacuum. I tried several chemical paint removers too, with and without paper over. None of those were completely successful, the best also removed glue between strips.
Since paint and primer worked well for decades, I stuck with it.

MN Dave
06-18-2018, 10:57 AM
I have seen a lot of suggestions for heat, but none for steam. It strikes me that the steam would weaken the bond between the paint and wood while dry heat might strengthen it. Steam also provides plenty of heat, but can't overheat and burn.

So with a little Google-fu, I found this:
Paint stripping with steam (https://thecraftsmanblog.com/how-to-strip-paint-part-3-steam-heat/)

Link to part 1 Chemical Stripping (https://thecraftsmanblog.com/how-to-strip-paint-part-1-chemical-strippers/)
Link to part 2 Scraping (https://thecraftsmanblog.com/how-to-strip-paint-part-2-scrape-like-a-pro/)
That blog has a lot of other paint stripping information (https://www.google.com/search?client=firefox-b-1&ei=Z9MnW-Bbi7ywBcvshcgI&q=site%3Athecraftsmanblog.com%2F+strip+paint&oq=site%3Athecraftsmanblog.com%2F+strip+paint&gs_l=psy-ab.12...23974.28254.0.30311.3.3.0.0.0.0.177.294.2j 1.3.0....0...1c.1.64.psy-ab..0.0.0....0.K0q7g_-Xozo).

Dave

wizbang 13
06-18-2018, 11:12 AM
I'm a fan of using epoxy on most boats, but not all.
In this case , it depends on stuff I don't know about the boat.
The width of the fir planks, the caulking technique,how the boat is kept/stored/ hauled.
CPES on bare wood can hardly be a bad thing. It will slow down absorption of water , but it will also slow down drying out. It will add a barrier to marine borers.
It will add insulation/isolation to potential threats of corrosion/ electrolysis.
One could consider it SUPERIOR primer, and switch over to conventional paint instead of more epoxy .
IF the boat is stable , (narrow planks/tight seams/no history of opening up),I would not hesitate to use an epoxy coating in lieu of one part alkyd/oil undercoater.
Top coat... That is another issue again.
IF the boat has wide planking with oakum banged in there , quarter inch linseed oil putty seam compound ,or wax,falling out , seams you can see through each spring.... then yes, stay with the caveman stuff.

jpatrick
06-18-2018, 12:05 PM
See this video for another way to remove paint:

https://www.offcenterharbor.com/videos/removing-paint-from-a-wooden-boat-rhythm-heat-and-a-scraper/

You have to sign up with Off Center Harbor to see the video, but that's not a bad thing. You can get 10 free views before buying a membership. Personally, I think it's worth every penny.

Jeff

Bob Cleek
06-18-2018, 02:16 PM
There must be hundreds of posts on how to strip and paint a hull on this forum. At this point, I'll just try to keep it as short as possible.

1. Strip paint with a heat gun or torch (if you know how to use one) and a sharp triangle scraper. Pros: many yards prohibit sanding without vacuum equipment. Heat and scraper is the least work by far, doesn't contaminate your surface with chemical and create huge messes like chemical strippers. Scrapings are easy to sweep up.

2. Conservatively sand wood fair. (No 40 grit disks on eight inch grinders!)

3. Apply CPES as per manufacturer's instructions. (This is a thin penetrating sealer, not adhesive epoxy resin.)

For topsides only:

4. Apply a few coats of sanding undercoat, preferably sprayed so as to avoid brush strokes. Cover to where surface is entirely pure white. (Gloss will not cover darks spots.)

5. Fill dings and divots with marine grade surfacing putty. (Most of the major marine paint companies offer this product. Do not use automotive two-part products, such as "Bondo!") If there are major gouges, these can be filled with epoxy adhesive and microballoons and faired. Sand with 220 grit until the surface is perfectly fair.

6. If surface is totally white, proceed to step 7. If not, repeat step 4. and 5. until surface is pure white and smooth as a baby's bottom. (This is the most important part of the entire job.)

7. Apply a minimum of three coats of properly conditioned gloss oil based enamel (Rx: Interlux,Petit, or Kirbys, the latter is a mail order product, but it comes with terrific telephone customer support and is probably the highest quality of all.) Some find "rolling and tipping" successful. Some make a dog's breakfast of it. Learning how to condition and apply paint properly with a brush or spray gun (which some yards prohibit unless you have a spray booth) will ensure a top notch job. If you don't know how to paint, one might consider hiring a pro to lay on the gloss top coat. The real labor is in the preparation of the surface, so you've already achieved the savings of DIY.

For bottom only:

Perform steps 1, 2, and 3 above.

4. Apply a marine-grade epoxy barrier coat if desired. (This will provide protection from marine borers to a certain extent.)

5. Apply anti-fouling paint as per manufacturer's instructions. First coat well thinned and worked in well, particularly in any cracks or seams. (Do not use rollers! They do not work the paint into the seams, but tend to just spread paint on the surface. It's generally the cracks and seams where the borers find a cozy home and start eating their way inward.) Apply second coat of bottom paint "full strength." Apply additional coat at least approximately a minimum of 18" below the waterline. (Extra protection needed there.)

Painting a boat is not the same as painting a house or a barn. Most any decent oil based alkyd paint will produce a good result in the hands of somebody who knows what they are doing. Even the most expensive paint will not cure improper application techniques, and this is especially so for the expensive two-part epoxies and urethanes, many of which are not suitable for wooden boats anyway.

gypsie
06-19-2018, 10:46 PM
Wow - thanks everyone.
There's definitely theme's emerging there that are useful.

I hear the advice on blasting and am thankful for it. I did have concerns about just raising the grain and wasn't enamoured of the idea.

I think I'll aim for smooth fair finish, even if that leaves a paint covered surface. So even heat may be too far - just go at it with a decent sander and scraper. I have a wide based belt sander, and various disks.
The CPES option is coming through as a good idea. I hadn't expected that. It's clear the advantages, but i was reticent about only doing one side of a plank only. My only thought now is that to apply the CPES would mean 'wooding' (thanks for the term David G) below the waterline. But that could be decided on how thorough the hull sanding is.
Planks are about 4 to 5" wide. Caulked seams filled with what looks like a modern filler - sikaflex or something. Does bulge in the heat, shows seams when its been sailed hard but then usually returns to pretty flat after a rest.

Below the waterline is built up with years of bottom paint, all pot marked and uneven, and its beginning to fall off in chunks about the size of my hand. I think when i go at it seriously with sander and scraper I'll expose quite a bit of wood.
The think the CPES as the primer, and work up from there.
I have been using International products as well.
I had toyed with 2 pack for the topsides, but I've found on my annual haul that two days, one overnight, gives me exactly the right time to powerhose the bottom, sand the topsides, anti-foul and give the topsides a full coat. Plus usually one or two other jobs on through hulls etc... So happy to plan for touch ups.

The Norglass products, the guy recommends, for the bottom, that I use their products up to the undercoat and then apply whatever antifoul i like. Do you think i should apply the appropriate (for the brand) anti-foul undercoat ontop of the Norglass undercoat?

This is great, not at all daunting like i thought it could be.
Appreciate your input everyone.

Thanks

T

Bob Cleek
06-21-2018, 12:27 PM
DO NOT take a sander to the bottom paint. You should use a heat gun and scraper only until you have pretty much all of the old bottom paint off. Bottom paint sanding dust is highly toxic and nasty even if you wear haz-mat gear and a mask with an air supply. Just don't go there. A lot of guys have ended up in the emergency room doing what you propose.

Aggressive sanding is generally a poor way to remove paint in any event. A heavy sander and coarse grit is very likely to result in divots. A belt sander shouldn't be used on anything but a flat surface anyway. If you want to sand after removing the worst of the paint, then use a variable speed automotive polisher (relatively slow RPMs... 2000, IIRC) with a seven or eight inch diameter foam sanding pad with adhesive sanding disks. This will conform to the curved surfaces of a boat much better and eliminate flat spots. The variable speed will allow you much greater control and minimize gouging.

One benefit of CPES on bottoms is the likely effect of deterring marine borers, on the surface, at least. (They do look for small entry points, though, and then eat beneath the surface, so make sure you get it covered well.)

Makita used to make a one-handed polisher/sander, but apparently no more. The current equivalent is their two-handed model.

https://pull3-thetoolnut.netdna-ssl.com/media/catalog/product/cache/1/image/1200x/9df78eab33525d08d6e5fb8d27136e95/m/a/makita-9227c-1.jpg

https://www.toolnut.com/makita-9227c-7-electronic-polisher-sander.html?msclkid=1635f4472f5e1a34b809af6cceeb2f a8&utm_source=bing&utm_medium=cpc&utm_campaign=*Shopping%20-%20Medium%20-%20Branded&utm_term=4578297703446764&utm_content=%24100-%24250

Put a foam sanding pad on it as pictured.

wizbang 13
06-21-2018, 12:53 PM
Get that handle off. The foam backer pictured is the 6 inch velcro thingy that comes with it..not suitable for bottom sanding.
If you are in a place, your yard, a field, a third world country, away from an American boatyard and can get away with it, a proper disc sander is the best way to remove bottom paint and fair a hull.The dust is being blown away from me here, blower just out of picture.I used to do this for a living.
https://farm9.staticflickr.com/8453/7994053151_5de610b951_z_d.jpg
You still need an after market backer. This one is a "Spiral Cool" brand.The black rubber backer that comes with a sander/polisher is made for a wool polishing bonnet, not a grinding disc.
https://farm5.staticflickr.com/4121/4942642136_79eb112c18_z_d.jpg

In a controlled place, a Festool Rotex with the correct dust collection tool is whats used. It's a thousand dollar system.

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=imgres&cd=&cad=rja&uact=8&ved=2ahUKEwjUr9Lgq-XbAhWUFzQIHQOIBaIQjRx6BAgBEAU&url=https%3A%2F%2Fwww.toucantools.co.uk%2Ffestool_ ro150_rotex_sander_and_ctl_midi_dust_extractor_kit .html&psig=AOvVaw1h-jgEkVeqyh_OlimRBbU6&ust=1529690617608826
https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=imgres&cd=&cad=rja&uact=8&ved=2ahUKEwjUr9Lgq-XbAhWUFzQIHQOIBaIQjRx6BAgBEAU&url=https%3A%2F%2Fwww.toucantools.co.uk%2Ffestool_ ro150_rotex_sander_and_ctl_midi_dust_extractor_kit .html&psig=AOvVaw1h-jgEkVeqyh_OlimRBbU6&ust=1529690617608826

Bob Cleek
06-25-2018, 12:28 PM
Wiz is right about the technique of using a big fan to blow the dust away from you, although note he's wearing lung protection nonetheless. This only works in unregulated areas, though. They'd hang you up by your thumbs for doing such a thing anywhere in the civilized world these days and I'm not taking the rap for encouraging anybody to employ the technique. They don't call him "Wizbang" for nothing. He's a Rembrandt with a grinder. Only the most skilled can get away with what he can. :D

gypsie
07-02-2018, 07:21 PM
Thanks Wizbang and Bob, i have access to a decent steam gun - I'll give that a go first off and then proceed to heat gun.
I'll just keep the sanding disk for the topsides to get it fair. I don't think i need to go down too far on the topsides. There's some pot marks where paint has flaked off, if I get them fair, get rid of anything loose or loose-ish, and than paint over as Bob describes.

Bob, you don't mention an undercoat for the bottom other than CPES as primer?

Thanks

Trev