I was planning to blast my hull using walnut shells, but I see that WM sells a chemical stripper to remove old bottom paint. Does anyone have experience with stripping a hull?
Thanks
Thanks
Chemical stripping hull vs blasting it
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Also, I assume I should not use this on an external iron keel as it is more porous and the stripper could keep paint from adhering.
You didn't say what size boat? I've done two in the last 6 years a Hunter 25 and a Hunter 28, both using a Random Orbit sander and 80 grit. I'm in Colorado and have a friends yard to work in vs. a stanard boat yard so, the dust may be a problem for some areas. It wasn't too bad of a job however it was very dirty (use a respirator and lots of sand paper). Other than tiring on the arms, it took about 12 actual hours to do the 28 and get to the gel coat and then I could put on 4 coats of interlux and my bottom paint.
I just did the 28 two seasons ago and it still looks brand new, we've been in fresh water so only deal with a little bottom growth but I've had no issues with my bottom (boat only) since the job was done
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I can' t speak to either the strippers or the sand blasting but sanding the old fashioned way worked for me very well as long as you don't mind the effort. And the results, especially on the 28, are worth the effort.
Good Luck
Victor
French Temper
Hunter 28
I just did the 28 two seasons ago and it still looks brand new, we've been in fresh water so only deal with a little bottom growth but I've had no issues with my bottom (boat only) since the job was done
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I can' t speak to either the strippers or the sand blasting but sanding the old fashioned way worked for me very well as long as you don't mind the effort. And the results, especially on the 28, are worth the effort.
Good Luck
Victor
French Temper
Hunter 28
Read the thread in this link before you decide
I stripped the bottom of my boat YESTERDAY. And I did a Rhodes 22 last summer.
And a MacGregor 22 three summers ago.... and a Coronado 23 five summers ago.
I've done the sanding, the citrus strip and.... starting last year I began using home made peel away.
(see link)
http://forums.sbo.sailboatowners.com/showthread.php?t=135880&highlight=Peel
Damn I wish I knew this trick earlier. If you follow the link, you will see before and after pics. It really works. And it is so inexpensive you can afford to do it two or three times on the few tough spots.
As a follow up to the advice in the link, I've found that citrus strip on the few tough spots that remain works best. I have used it on three different boats and the gel coat was fine afterwords on all three.
Lastly, 3M makes an abrasive pad (similar to the green pads you use to scrub pots) that is made for stripping paint. You can get them at Lowes. They fit in an orbital sander
That will power through any remaining remnants in seconds. You can have your bottom stripped in about 5 hours of actual work.
r
I stripped the bottom of my boat YESTERDAY. And I did a Rhodes 22 last summer.
And a MacGregor 22 three summers ago.... and a Coronado 23 five summers ago.
I've done the sanding, the citrus strip and.... starting last year I began using home made peel away.
(see link)
http://forums.sbo.sailboatowners.com/showthread.php?t=135880&highlight=Peel
Damn I wish I knew this trick earlier. If you follow the link, you will see before and after pics. It really works. And it is so inexpensive you can afford to do it two or three times on the few tough spots.
As a follow up to the advice in the link, I've found that citrus strip on the few tough spots that remain works best. I have used it on three different boats and the gel coat was fine afterwords on all three.
Lastly, 3M makes an abrasive pad (similar to the green pads you use to scrub pots) that is made for stripping paint. You can get them at Lowes. They fit in an orbital sander
That will power through any remaining remnants in seconds. You can have your bottom stripped in about 5 hours of actual work.
r
Re: Read the thread in this link before you decide
Hmm- certainly sounds like easiest and probably cheapest, Rgranger.
How have you handled the containment of the mess and the cleanup? If you power wash off, doesn't the stuff fly all over? Do you put a tarp down first?
Hmm- certainly sounds like easiest and probably cheapest, Rgranger.
How have you handled the containment of the mess and the cleanup? If you power wash off, doesn't the stuff fly all over? Do you put a tarp down first?
Ah yes... good point. The first time I did it, I did not plan ahead and it was a big mess. I ended up taking a garden rake and hoe and pushing all of the scale into a pile and then sucking it up with a shop vac. Probably did not get it all. However copper (the toxin in most bottom paint) is actually a trace nutrient for terrestrial plants although it is very toxic to marine life. So I probably have a spot in my yard with higher than normal copper but I hope I recovered enough of it to keep it within tolerance levels. :neutral:
After that I got smarter and put down some of that cloth used in landscaping. You know the stuff? It is supposed to keep weeds from coming up under your mulch but it lets water through. I had a big roll left over from a yard project. Anyway, the water from the power washer got through but the cloth effectively trapped all of the scale. It worked very well. I think a tarp would be a bad idea since it would form a big puddle and be a big mess <speculation>.
Ahh- didn't think of the water collection aspect- I do have some of that landscaping fabric- good thought.
Could you post your latest recipe in fairly exact terms- I am supposing you have been improving it s you worked through three boats. How much water do you dd after the dry ingredients- do you just go by consistency? I think this will bethe route I go this summer to strip my 34.
Thanks- this is what makes this a great forum- all this info, tried and true, out there in people's heads.
Could you post your latest recipe in fairly exact terms- I am supposing you have been improving it s you worked through three boats. How much water do you dd after the dry ingredients- do you just go by consistency? I think this will bethe route I go this summer to strip my 34.
Thanks- this is what makes this a great forum- all this info, tried and true, out there in people's heads.
Its really awesome to come across this. I did a few searches a while back trying to figure out a diy option but came up short.
Curious how safe this stuff would be on a metal structure, like a car body, or in my case, a Bus. The Bus is stainless sheets riveted to steel tubing with stainless rivets. I don't believe the stripper will get under the panels but am concerned should that occur.
Curious how safe this stuff would be on a metal structure, like a car body, or in my case, a Bus. The Bus is stainless sheets riveted to steel tubing with stainless rivets. I don't believe the stripper will get under the panels but am concerned should that occur.
I had the fiberglass part of the hull soda blasted then sandblasted the cast iron keel. Three coats of epoxy and then two coats of bottom paint. I used to sand the hulls every year by hand, but as the boats grew larger I said the heck with it. That was before I had ever heard of soda blasting. It is my opinion soda blasting leaves the hull in much better shape and requires less touch up. It is always a mess no matter how you do it. Soda blasting is done dry. Plus their units are mobile.
Well the most recent (last weekend) batch was a 5 gallon PVC bucket with about 2 gal. of water, a 40 lb bag of garden lime (a.k.a. quick lime or unslacked lime) and about 2 lb of KOH. I'm a chemist so I can get KOH. But you will probably need to get two or three large cans of drain-o or some other hydroxide based drain cleaner or canning lye. It is okay to use NaOH if you can find it. I like using KOH because the potassium (K) is good for the soil. But actually the sodium version will dissolve faster.
Stir it up until it is like pancake batter and roll it on the boat with a paint roller on a LONG pole. I use a piece of conduit for the stir rod. Wear eye protection and also some eye protection and also make sure you have on eye protection.
Keep a jug of white vinegar nearby in case you spill it on your arms or legs.
In the past I have added sugar and once before I tried glycerine to help keep it moist while on the hull. If it dries all the way out it stops being effective. I think it worked a little better that way but I didn't do it that way this most recent time. I just applied a second coat and blasted again with the pressure washer.
Don't let it sit more than two days or it will start to turn into a very hard substance that will be difficult to get off of the hull (carbonates).
Oh yeah... and make sure you have some eye protection.
The chemistry of lime is very similar (and related to) the chemistry of concrete, brick mortar and cement. It is all alkali (basic) It is generally accepted that concrete and cement have a protective property when it comes to metals in contact with concrete and cement. For example rebar is just plain old cast iron but it holds up well in the wet environment of a foundation. On the other hand, acids are tough on metals. It is RedOx chemistry.
If you have something metal (maybe some cast iron lawn furniture) that you could put a dab onto and let it sit a few days... you could test it and make sure (peace of mind) before you try it on something more precious to you.
In my refit i had to remove absurd amounts of paint and even at 55 years old i had way more elbow grease then money in my refit budget for paint striper
Once you get your Scraping Zen going the paint comes off pretty fast in the cheapest possible way and lowest disposal issues
Wow, lots of interesting input. I was shocked when I realized that 5 gal. of chemical stripper form WM would cost as much as 300 lbs. of walnut shells. So I'm glad to see that this concoction is dirt cheap.
Rgranger, after reading, I'm not surprised to find out that you're a chemist. I hated Chemistry 101...all four times, so I appreciate your taking time to explain it for me.
So here's the recipe:
Don bunny suit, gloves and eye protection. In a 5 gallon PVC bucket mix 2 gal. of water, a 40 lb bag of garden lime (a.k.a. quick lime or unslacked lime) and two or three large cans of drain-o or some other hydroxide based drain cleaner or canning lye. Apply using a roller on a long handle, pressure wash off soon after it has dried.
Does 40 lbs. of lye fit in a 5 gal. bucket?
Also, it sounds like I can use this stripper on the iron keel, too?
Thanks.
Rgranger, after reading, I'm not surprised to find out that you're a chemist. I hated Chemistry 101...all four times, so I appreciate your taking time to explain it for me.
So here's the recipe:
Don bunny suit, gloves and eye protection. In a 5 gallon PVC bucket mix 2 gal. of water, a 40 lb bag of garden lime (a.k.a. quick lime or unslacked lime) and two or three large cans of drain-o or some other hydroxide based drain cleaner or canning lye. Apply using a roller on a long handle, pressure wash off soon after it has dried.
Does 40 lbs. of lye fit in a 5 gal. bucket?
Also, it sounds like I can use this stripper on the iron keel, too?
Thanks.
This is frikin awesome!
I have to strip my Mac 26D from top to bottom. I have a couple cans of the safest stripper but not enough for the whole job.
A few questions;
1; Once stripped, can the gelcoat be brought back or is it a got to paint type deal? (Does it hurt the gel like etch it in any way?)
2: Will this remove "tea stains"? You know that icky brown stuff.
3: Rub rail? Will it melt it?
4; Is it a good idea to wear personal protective equipment like goggles and gloves?
Pic= fancy tea stains. No biscuits.
Edit: What about covering it.... I do this with regular stripper and 6mill plastic on wood. Will it work on this. Too well?
(Here is how I would do it: cut long strips of plastic and lay them under the boat. Apply stripper and lift plastic into place. Tape to cabin top as needed. Cover smaller areas with small pieces.) That's just my idea. Do waht you want.
I have to strip my Mac 26D from top to bottom. I have a couple cans of the safest stripper but not enough for the whole job.
A few questions;
1; Once stripped, can the gelcoat be brought back or is it a got to paint type deal? (Does it hurt the gel like etch it in any way?)
2: Will this remove "tea stains"? You know that icky brown stuff.
3: Rub rail? Will it melt it?
4; Is it a good idea to wear personal protective equipment like goggles and gloves?
Pic= fancy tea stains. No biscuits.
Edit: What about covering it.... I do this with regular stripper and 6mill plastic on wood. Will it work on this. Too well?
(Here is how I would do it: cut long strips of plastic and lay them under the boat. Apply stripper and lift plastic into place. Tape to cabin top as needed. Cover smaller areas with small pieces.) That's just my idea. Do waht you want.
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First off I can't take credit for this recipe. Ross (also on this forum) mentioned in a post a while back that peel away was just lime and a hydroxide. The lime is just a binder ... it is the hydroxide that breaks down the polymer in the paint.
I'd let it sit a while. Don't spray it off right away. Roll it on in the evening so it will stay moist longer. Maybe apply a second coat to re-wet it first thing in the morning the next day... and pressure was that afternoon. [/quote]
It fits in mine... my bucket might be a 7 gallon. I got it from work and it was originally used for floor wax.
Yes! I've used it on mine with no problem.
I much prefer soda
Soda blasting by far for me is an easy choice. It's no as abrasive as sand or walnut shells, is easy to do, and there is nothing toxic in it. First rain and it cleaned up completely.
Soda blasting by far for me is an easy choice. It's no as abrasive as sand or walnut shells, is easy to do, and there is nothing toxic in it. First rain and it cleaned up completely.
I did this last summer on a Rhodes 22. The pics seen in the above link were from that boat. Much of the gel coat came back to life but there were places where the hull had been scratched up where the pigment in the paint leached into the gel coat. The color was mostly in the grooves. So I guess it depends. On the Balboa I did this weekend, the paint is mostly gone (a few stubborn spots) but the hull remains a light blue. I'm not sure if that was the original gel coat or if the blue is from ablative bottom paint.
I don't know but I doubt it. That is most likely tannins. Oxalic acid should take that off. You can get it as "wood bleach" in the deck cleaning section of Lowes or as "Bar Keepers Friend".
I've only ever used this to remove ablative bottom paint. So I don't know. I doubt that butyl rubber would be harmed by KOH so I suspect your rail would be fine. Test it first on a small section.
Absolutely on the goggles. Don't go near this stuff without eye protection. I also keep vinegar handy in case I get it on my skin. It will leave a nasty chemical burn and severe chapped skin if you get it on your skin and don't get it off right away.
That is what the commercial peel away folks do. It is supposed to keep it from drying out so fast.... that way the KOH has more time to do it's thing. I did not try it but I like your idea and method and will try it next time. I added glycerine to my mix. That seemed to work some but I suspect your method is better. Glycerine holds moisture from the air (it is also used to keep your twinkies and Red Man moist).
What is the "soda" in sodablasting? Is it NaHCO3 (a.k.a. baking soda)? or crushed lime? or pot ash? I'm not that familiar with it.
I just purchased a sandblaster and might want to experiment with a few other abrasives.
"Glycerine holds moisture from the air (it is also used to keep your twinkies and Red Man moist). "
The Twinkies secret is out!
What do you know about those McDonalds apple slices that lasted over 3 mo (summer) opened in my work van? Looked like new.
The Twinkies secret is out!
What do you know about those McDonalds apple slices that lasted over 3 mo (summer) opened in my work van? Looked like new.
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