Plan to clean the bottom of my CD28 down to the gelcoat this year, followed by the application of several coats of sealer and anti-fouling paint. Question is, what's the best method of stripping the accumulated layers off while doing as little damage as possible to the gelcoat? Any thoughts out there.
Tom Johnston
s/v Kayla
CD28 #318
tjsan@atlantic.net
Stripping Bottom Paint
Moderator: Jim Walsh
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Why I like my small Dory
Re: Stripping Bottom Paint
Tom,
I just finished stripping my 25D (20 years of build-up by the previous owner) and used Peel Away based on the Recommendation in Practical Sailor (September 2000). It's supposed to be environmentally safe and easy on your gelcoat.
It's a messy job; and expensive. I needed 3 gallons at $159 ea (you might come out ahead with the 5 gallon tub for $229.)
I lost some skin on one hand, but not to the Peel Away. The cheap rubber gloves I bought protected me from the Peel Away (and when I got some on me, I just wiped it off), but the mineral Spirits wash required to complete the job is rough. It burns and broke down eight pair of my gloves.
I did the job in four sections allowing the product to work for six hours before stripping. I tried to remove some paint after four and a half hours and couldn't get all the layers. The stripping/cleaning step takes about 3 times as long as the application step and limits how much you can get done in a day. The shorter days work against you. Time to percolate is very important and apparently so is temperature! I had four days with highs in the low 70's each day so I recommend you try a small section to determine how long to let it work under your current temps, and just how much work you want to face each day (I could have done the job in two days in July, but probably would have been wasted by the effort (the cleaning step with the mineral spirits is the worst part -- and can hurt you).
Expect to throw away whatever you're wearing.
Good luck
Garrard
PS Practical Sailor's latest comparison of bottom paints is in their March '01 issue.
gypsite@mindspring.com
I just finished stripping my 25D (20 years of build-up by the previous owner) and used Peel Away based on the Recommendation in Practical Sailor (September 2000). It's supposed to be environmentally safe and easy on your gelcoat.
It's a messy job; and expensive. I needed 3 gallons at $159 ea (you might come out ahead with the 5 gallon tub for $229.)
I lost some skin on one hand, but not to the Peel Away. The cheap rubber gloves I bought protected me from the Peel Away (and when I got some on me, I just wiped it off), but the mineral Spirits wash required to complete the job is rough. It burns and broke down eight pair of my gloves.
I did the job in four sections allowing the product to work for six hours before stripping. I tried to remove some paint after four and a half hours and couldn't get all the layers. The stripping/cleaning step takes about 3 times as long as the application step and limits how much you can get done in a day. The shorter days work against you. Time to percolate is very important and apparently so is temperature! I had four days with highs in the low 70's each day so I recommend you try a small section to determine how long to let it work under your current temps, and just how much work you want to face each day (I could have done the job in two days in July, but probably would have been wasted by the effort (the cleaning step with the mineral spirits is the worst part -- and can hurt you).
Expect to throw away whatever you're wearing.
Good luck
Garrard
PS Practical Sailor's latest comparison of bottom paints is in their March '01 issue.
gypsite@mindspring.com
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John Nuttall
Sandblast with Walnut Shells......
......no, this is not a joke !!!
Cracked Walnut shells will blast off the paint and not harm the gel coat. They are regularly used for blasting items that sand would tear up. The Walnut Shells are terribly expensive, compared to sand. But not compared to Peel Away + paint thinner + Gas Masks + Rubber Gloves + Skin Ointment + time + aggravation + mess and clean up!!
Once you get the machine adjusted you'll be able to do a good & quick job of it. I took the bottom paint off my Sonar (close in size/dimension to a J24 ) in a short afternoon. Two boat owners in the same boatyard could split the cost and double team 2 boats in a day !!!
You should be able to get the Walnut shells from the same rental company that provides the sandblaster. I put a cheap plastic tarp under the boat to capture the shells and was able to recycle the shells thru the machine a couple times..... The rental company won't like that, but that can be our secret !... ;-} Once you are done, fold up the plastic tarp with all the shells/paint and chuck it in the dumpster!
Then it's time to break out the sander....but that's another subject !
John
s/v Aimless
CD31 #28
in the yard, back in on Monday for another season of Winter Sailing in NC !!! Aye, the yard bill has kicked the jack tar out o' me...
aimless@nc.rr.com
Cracked Walnut shells will blast off the paint and not harm the gel coat. They are regularly used for blasting items that sand would tear up. The Walnut Shells are terribly expensive, compared to sand. But not compared to Peel Away + paint thinner + Gas Masks + Rubber Gloves + Skin Ointment + time + aggravation + mess and clean up!!
Once you get the machine adjusted you'll be able to do a good & quick job of it. I took the bottom paint off my Sonar (close in size/dimension to a J24 ) in a short afternoon. Two boat owners in the same boatyard could split the cost and double team 2 boats in a day !!!
You should be able to get the Walnut shells from the same rental company that provides the sandblaster. I put a cheap plastic tarp under the boat to capture the shells and was able to recycle the shells thru the machine a couple times..... The rental company won't like that, but that can be our secret !... ;-} Once you are done, fold up the plastic tarp with all the shells/paint and chuck it in the dumpster!
Then it's time to break out the sander....but that's another subject !
John
s/v Aimless
CD31 #28
in the yard, back in on Monday for another season of Winter Sailing in NC !!! Aye, the yard bill has kicked the jack tar out o' me...
aimless@nc.rr.com
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Jon
Re: British Seagull
Get a British Seagull, tape sandpaper to each of the 5 blades, and use it like a weedwacker. That's about all those motors are good for.
Jon
CD25 Sovereign
Jon
CD25 Sovereign
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Michael Heintz
Comming from John NUT TALL I wonder.........
Captain John,
No offense or anything....... BUT...is this a TALL NUT tale ?
Captain Commanding
Macht Nichts
CD 30 MK II 004
Mzenith@aol.com
No offense or anything....... BUT...is this a TALL NUT tale ?
Captain Commanding
Macht Nichts
CD 30 MK II 004
Mzenith@aol.com
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Bob Chamberland
Re: Sandblast with Walnut Shells......
Hi John,
What kind of surface is the result of blasting with walnut shells? Would it really need sanding? It would seem to be a good time to put on a barrier coat THEN SAND. I've sandblasted with "sandbox" sand and seen it eat up a fibreglass patch in a flash. Walnut shells are slower and gentler? Please elucidate what happens after blasting?
Bob Chamberland
cha62759@traverse.com
What kind of surface is the result of blasting with walnut shells? Would it really need sanding? It would seem to be a good time to put on a barrier coat THEN SAND. I've sandblasted with "sandbox" sand and seen it eat up a fibreglass patch in a flash. Walnut shells are slower and gentler? Please elucidate what happens after blasting?
Bob Chamberland
John Nuttall wrote: Then it's time to break out the sander....but that's another subject !
John
s/v Aimless
CD31 #28
in the yard, back in on Monday for another season of Winter Sailing in NC !!! Aye, the yard bill has kicked the jack tar out o' me...
cha62759@traverse.com
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John Nuttall
Well I am 6'4"....................
Capt'n Heintz,
Your rapier wit is sharp, and duly noted...touche !!!
However I suggest you hone a fine edge on your stem sir, lest that scoundrel Cap'n Stump get an advantage over M.N. !
The Nut
aimless@nc.rr.com
Your rapier wit is sharp, and duly noted...touche !!!
However I suggest you hone a fine edge on your stem sir, lest that scoundrel Cap'n Stump get an advantage over M.N. !
The Nut
aimless@nc.rr.com
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John Nuttall
Depends on how much time...
.......you put into it.
We were prepping the bottom for racing. Dry sailing. We wet sanded down to 600.
The walnut shells will eventually eat thru gel coat too, but you would have to really work at it. You really can get off all the old bottom paint and leave nothing but gel coat. If I had to guess I say equivalent to a 220 grit finish. Probably not enough tooth there for a barrier coat I'd guess.......but easy enough to wetsand with a coarser grit if that's what's called for.
Today I was at the yard talkling with my painter and he mentioned there are better substitutes nowadays for walnut shells. synthetics. He mentioned the EPA is all over the silica dust (or was it OSHA?.) so many alternatives to sand have been developed.
Care to do a little Web research and get back to us ???
John NUTtall
aimless@nc.rr.com
We were prepping the bottom for racing. Dry sailing. We wet sanded down to 600.
The walnut shells will eventually eat thru gel coat too, but you would have to really work at it. You really can get off all the old bottom paint and leave nothing but gel coat. If I had to guess I say equivalent to a 220 grit finish. Probably not enough tooth there for a barrier coat I'd guess.......but easy enough to wetsand with a coarser grit if that's what's called for.
Today I was at the yard talkling with my painter and he mentioned there are better substitutes nowadays for walnut shells. synthetics. He mentioned the EPA is all over the silica dust (or was it OSHA?.) so many alternatives to sand have been developed.
Care to do a little Web research and get back to us ???
John NUTtall
aimless@nc.rr.com
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Ed Roberts
Re: Stripping Bottom Paint
I had a bottom stripped by a fellow who used his rig primarily for aircraft paint removal. He "sand-blasted" with plastic pellets which he could select for hardness, acording to the surface and paint. I guess the detective work should start by inquiring around an airport.
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JimL
Re: blasting media
Sears has a special catalog for automotive restoration work. In that catalog they offer media blasters and choices of walnut shell, hard plastic beads, soft plastic beads, etc. You'll also find equipment and media available (from a number of sources) in Hemmings Motor News. Hemmings is dedicated to cars/parts/equipment for restoration and projects.
Hope this helps. For anyone interested, I made my bottom sanding job a lot easier by getting one of the disposable PPG suits (automotive body shop supplier), complete with clear faceplate air hood. The hood has a nipple on the back, for input air flow. I taped a piece of 1" plastic hose, 25 feet long, into it (make the hose stick all the way up the back of your head), then duct taped the other end to an old hair dryer (no heat element). With a large automitive air filter duct taped to the inlet side of the hair dryer, you have a clean, cool, dust free air supply. This lets you get up close to the work, so your arms don't get so tired. When the job is done, step out of the suit and you'll be clean and cool!
I used a DA (dual action) air sander with NoFil pads (velcro type, easy to change with gloves), 100 grit. All done in 2 hours and came out great.
Hope this helps. For anyone interested, I made my bottom sanding job a lot easier by getting one of the disposable PPG suits (automotive body shop supplier), complete with clear faceplate air hood. The hood has a nipple on the back, for input air flow. I taped a piece of 1" plastic hose, 25 feet long, into it (make the hose stick all the way up the back of your head), then duct taped the other end to an old hair dryer (no heat element). With a large automitive air filter duct taped to the inlet side of the hair dryer, you have a clean, cool, dust free air supply. This lets you get up close to the work, so your arms don't get so tired. When the job is done, step out of the suit and you'll be clean and cool!
I used a DA (dual action) air sander with NoFil pads (velcro type, easy to change with gloves), 100 grit. All done in 2 hours and came out great.
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Mark Yashinsky
Poly beads
Given enough time and effort, almost anything will eat thru the gelcoat, even water (4-5000psi, and a turbo nozzle will punch thru a 2x4). Poly beads ARE "designed" for use on thin and soft surfaces, like sheet metals and fiberglass. Shells are a more abrasive and require more experience and care (and can be faster). Poly is also more expensive (~$2/lb) vs walnut shells (~$.5/lb). Care is the same if you go the sanding route. Coarser paper means faster removal, but greater care and greater possibility of gel penetration. FYI, a number of years ago, assisted Bill Goldsmith (Second Chance) on removing all the bottom paint using random orbit sanders (vacuum connections) in prep for a complete West System barrier coating. The sanding was easy and quick, the epoxy was the "fun" stuff.
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Jerome Basma
Re: Stripping Bottom Paint - try a scraper...
Tom,
About taking off years of bottom paint, you might try using a scraper (the ones that look like putty knives) which is what I did on the bottom of my Typhoon. To make the task easier, take an old piece of standing rigging to use as a whip. Whack the hull with it and watch the chips fall off. After a few whacks you can go in with the scraper and take off large areas. For especially large areas, I've seen a friend use a scraper attached to a long handle.
Jerome, SV "Io"
jbasma@aol.com
About taking off years of bottom paint, you might try using a scraper (the ones that look like putty knives) which is what I did on the bottom of my Typhoon. To make the task easier, take an old piece of standing rigging to use as a whip. Whack the hull with it and watch the chips fall off. After a few whacks you can go in with the scraper and take off large areas. For especially large areas, I've seen a friend use a scraper attached to a long handle.
Jerome, SV "Io"
jbasma@aol.com