Old bottom paint removal

[Heckler]

My 2001 Grady Express has enjoyed the benefits of ablative bottom paints for only half half of its life. Before that each year the hull would get another spring coat of bottom paint building upon the thicknesses of the prior years, That build up has been coming off down to the gelcoat in small bits and pieces (between a quarter size and dollar bill size) each year and even though those spots are repainted, there are plenty more pieces of paint to come off the following year.
Needless to say it creates a very rough surface to the water flow and when visible above the water line when running, an unsightly appearance.
I am on Martha's Vineyard and have access to boat yard locations on the south side of the Cape-or in Buzzards Bay.

Questions:
What are the processes and materials are now being used to blast off the old paint and get back to the smooth gelcoat.

Also can anyone recommend a boat yard that provides this service and the potential cost ?

Thanks in advance for the information

 

[seasick]

What was once sand blasting now uses a lot of abrasives, just not sand I suppose soda blasting is the popular one but many materials like walnut husks or glass beads have been used .
The challenge is to find a good person/company to do the blasting. It is relatively easy to blast away too much of the gel coat. After blasting, some sanding may be needed and usually I suggest that barrier coat be applied especially if the gel coat is worn. The trick to barrier coats is to follow the directions to the T and that includes taking into account the temperatures and the recommended times between coats and the application of the bottom paint. The last Interlux 2000 barrier painting I did took 3 days when heeding the directions for wait times and final paint. Some of the other barrier coats are not as picky from what I read, but I haven't tried any of them.
Also for recommendations it would help to know where you are located.

 

[SeaVee]

Farrow blasting

 

[DennisG01]

I'm sure where you are in Mass there will be plenty of options for you. There might even be a mobile soda blasting company - if you google for that, you'll probably find some businesses. You could also try contacting a few marinas in the area to see if they do it - or who they would recommend.

It sounds like you want to get back to clean/new looking fiberglass and keep it that way. Note that it won't look like that when the blasting is done. The soda blasting won't damage your gelcoat, but there's basically two ways to initially prepare gelcoat for bottom painting. One is physical sanding, the other is chemical etching. Both leave the gelcoat "ugly". To fix it, will require sanding/buffing.

 

[leeccoll]

Heckler,

I can't tell you which shop to try, but just had my '87 228 bottom paint removed.
You can find out other peoples experiences in your area on "yelp".

Although mine was sanded off-not blasted I paid $2,400, but that included fiberglass work to repair damage to the strakes and keel from my trailer, and a few other repairs where I was lazy with Marine-Tex sanding. And gelcoat was applied to the fixed areas. Probably would have been $1,800 without the extra repairs.

Happy as a clam now with my bottom

Here's thread on mine if you want removal details. A lot of ways to skin the cat to get the paint off.

228G Bottom Paint Removal

Decided last fall to splurge and have my bottom paint removed on my 1987 228 hull. It's been in the shop for about a month, and stopped in for a peek today. Amazing transformation so far. My Venture cheapo trailer had chewed up the strakes down to the fiberglass in areas, and the keel also was...

www.greatgrady.com

Good luck with this,

Lee

 

[Heckler]

Thanks to all for the information and caveats and I will explore all the options suggested.

I'll also let you know what I discovered.

I don't trailer my 265 Express, so a mobile service would have great advantages. Otherwise I would launch the boat in the spring , run it to the selected source, have them haul it, do the job and paint the bottom and relaunch. Certainly a bit more complicated than having someone come to me while it is still on the hard.

Thanks again,

PS Seasick: I am on Martha's Vineyard , in the warmer weather- May thru October - it is moored in Tashmoo.

 

[Deep Blue]

My 2001 Grady Express has enjoyed the benefits of ablative bottom paints for only half half of its life. Before that each year the hull would get another spring coat of bottom paint building upon the thicknesses of the prior years, That build up has been coming off down to the gelcoat in small bits and pieces (between a quarter size and dollar bill size) each year and even though those spots are repainted, there are plenty more pieces of paint to come off the following year.
Needless to say it creates a very rough surface to the water flow and when visible above the water line when running, an unsightly appearance.
I am on Martha's Vineyard and have access to boat yard locations on the south side of the Cape-or in Buzzards Bay.

Questions:
What are the processes and materials are now being used to blast off the old paint and get back to the smooth gelcoat.

Also can anyone recommend a boat yard that provides this service and the potential cost ?

Thanks in advance for the information

I went down to my local yard with pretty much the same questions, they said they use a chemical stripper (where was she when I was in college?) instead of media blasting because it's gentler on the hull and fairly quick - they roll it on and let it work. I have no idea if it's faster or not. Since the yard in Newport Beach is next to some high end neighborhoods they may have changed from blasting due to the noise and dust.

 

[Heckler]

I went down to my local yard with pretty much the same questions, they said they use a chemical stripper (where was she when I was in college?) instead of media blasting because it's gentler on the hull and fairly quick - they roll it on and let it work. I have no idea if it's faster or not. Since the yard in Newport Beach is next to some high end neighborhoods they may have changed from blasting due to the noise and dust.

Ha! Thanks Deep Blue. It is probably worth exploring that alternative, but I was unaware that there were those products that really worked -especially for say an 8 (?) coat build up. It might be fun to try a chemical stripper however.

 

[DennisG01]

It might be fun to try a chemical stripper however.

I have tried them...

They work fine, but it's not faster. Also, soda blasting does not harm the hull in any way. Plus, plus... a good mobile soda blaster will tent the boat such that they collect all of the blasted off material and the "soda". Actually, soda blasting is infinitely times faster... writing a check is heck of a lot faster than being on your back for hours. Unless you're a glutton for punishment (including the following week of being sore), this is one of those times where you simply say "Who do I make the check out to".

You're NOT planning on putting anti-fouling paint back on, right?

 

[Heckler]

I have tried them...

They work fine, but it's not faster. Also, soda blasting does not harm the hull in any way. Plus, plus... a good mobile soda blaster will tent the boat such that they collect all of the blasted off material and the "soda". Actually, soda blasting is infinitely times faster... writing a check is heck of a lot faster than being on your back for hours. Unless you're a glutton for punishment (including the following week of being sore), this is one of those times where you simply say "Who do I make the check out to".

You're NOT planning on putting anti-fouling paint back on, right?

I wouldn't if I didn't have to. My boat is launched in early MAY and stays wet until late OCT so the growth of grass, slime and barnacles would be off the charts even by mid summer without it. I wish there was another practical way other than paint.
Thanks

 

[DennisG01]

Oh, OK. You initially posted you wanted to get back to smooth gelcoat, so that sounded like you wanted a shiny bottom

Google for mobile soda blasting (if you want to go that direction) - I'm sure you can figure out something that will work.

Install a lift? Got any hi-n-dry's nearby?

 

[Heckler]

Understand. Thanks

To all, l am still trying to Goggle mobile soda blasters (and every other combinations of possible names) as it is clear that service for my situation would be best by far. I'll let you-all know what I find. There have to be a lot of non-trailered boats in the area of Cape Cod and the Islands with the same bottom condition that would be their customers !

If this turns up negative, I will work the boatyards for a more complicated 'launch /haul out/ fix/ repaint /relaunch' sequence.

I think the chemical stripper idea was just a fantasy- hmm! ....don't have the energy for that.

 

[DennisG01]

I didn't click on any of the search results, but there seem to be a bunch:

mobile soda blasting near cape cod ma - Google Search

 

[max366]

Try a search on the Cape Cod Craiglist for "boat bottom". There are a few mobile blasting listings including one that uses glass beads. Claims to be better than soda. He's in RI and could easily take the ferry from Woods Hole. I'll be curious what you find - I'm in Falmouth and am considering doing my 2004 265 bottom. I had pricing of $800 for soda a few years ago, done in my yard with my boat on stands and blocks.

 

[Heckler]

Thanks DennisG01 and Max366 ! Great work!

Looks look like a number of high potential solutions ! Give a few days and I'll let you all know what I discover.

Much appreciated.

 

[Fishtales]

This is something I need to investigate. With a boat I don't trailer it is tricky to arrange. Not sure my yard would let me do it there. Some day.

 

[Toothpick 10]

I had the same situation as the OP. Believe it or not, I bought a fairly inexpensive electric pressure washer from HD and removed about 95% of my old peeling bottom paint with that pressure washer. I then used a scrapper to remove the remnants. I then applied a new coat of Petit ablative and it performed very well last season.

 

[Heckler]

On the subject of soda ( or other media ) blasting of bottom paint, i contacted 4 companies in the New England area with the following result for my 26.5 ft boat.

The price for this service alone was not less than 1500 dollars. if they had to travel, the distance added to the price. the boat owner the has to apply 2 coats of the epoxy sealer and two coats of bottom paint . Materials cost alone if you do t yourself is close to $600

Then there is the complexity of finding a place to have the work done. if you trailer your boat then you can go to the source. If not you have to find a yard that will support ths whole deal. they may wish to do the seal and paint as part of their benefit . but that another increment of cost.

If I have others do the work and need to haul and launch I an get estimates close to $5k.

Bottom line is that it reached the point that is not justifiable to give further thought, the boat is fine: sound and safe.
I might just work on the parts of the bottom that can be seen in normal use fr an aesthetic improvement and be happy with a rougher bottom and
a little less gas mileage.

 

[DennisG01]

That's a lot more expensive than it is around here - last time I checked, anyways. But you shouldn't need the epoxy sealer - not sure why they were telling you that, other than to CYA.

With that in mind, though, maybe you'd be happy with just a really strong pressure washing since that can do a pretty good job (although not perfect, of course) of knocking a lot of the old paint off. It will definitely make a dramatic difference.