Hi fellow sailors, I would like to know if any of you had already try to remove the bottom paint using a very high pressure water compressor. Normal machine normally push up the water to 2000 PSI, but I was wondering if I was using a real good compressor it could work. My bottom paint if flaking quite easily and a 4000 PSI machine is usually use for removing graffiti and wash concrete, so it should get rid of a bottom pretty easily, right ? My other question is : With this kind of pressure, could it be armful for the gelcoat ? I know that blisters is caused by water passing trough gelcoat, so I was asking my self that it might be possible for water particles to be push trough the gelcoat by this kind of pressure ? If so, how many days should I wait before applying the first coat of primmer to avoid imprisoning water in the hull ? Thank for your comments
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IMO not a good idea because.......
I have seen gouging damage to the gelcoat with a 3000# pressure washer. If the wand is not moved quickly over the surface it will allow the water to dig into the gelcoat. Unfortunately this is fairly easy to happen and care must be used for even normal pressure washing to remove bottom growth. I guess what I'm saying is that by the time you get enough pressure to actually remove the bottom paint, you will also be removing the gelcoat.
I have seen gouging damage to the gelcoat with a 3000# pressure washer. If the wand is not moved quickly over the surface it will allow the water to dig into the gelcoat. Unfortunately this is fairly easy to happen and care must be used for even normal pressure washing to remove bottom growth. I guess what I'm saying is that by the time you get enough pressure to actually remove the bottom paint, you will also be removing the gelcoat.
not a good shortcut
To reiterate Rich's reply, it can easily damage the gelcoat even if you are very careful. If it were that easy, we'd all have 4000psi pressure washers. I admire your attempt to find a better method but unfortunatley, the only good way of removing old bottom paint is the old-fashioned labor-intensive approach.
To reiterate Rich's reply, it can easily damage the gelcoat even if you are very careful. If it were that easy, we'd all have 4000psi pressure washers. I admire your attempt to find a better method but unfortunatley, the only good way of removing old bottom paint is the old-fashioned labor-intensive approach.
2400 psi
I used a 2400 psi machine to blow the algae off the bottom of my boat, I was not that careful, and had no resulting damage. It was enough power to blow off dangling algae, but not the little dots that anchor the algae to the boat. I used On and Off Hull cleaner with a stiff bristle brush to get the dots off.
I used a 2400 psi machine to blow the algae off the bottom of my boat, I was not that careful, and had no resulting damage. It was enough power to blow off dangling algae, but not the little dots that anchor the algae to the boat. I used On and Off Hull cleaner with a stiff bristle brush to get the dots off.
Only...
use enough pressure to get under those loose flakes of paint. Point wand at an angle of 150 degrees to the surface and keep it moving. Don't use the pressure head that has that pin-hole... no matter what you do! Get what you can with the pressure washer... hit the rest with a scrapper; sand; wipe down... and you are good to go. I have had good luck getting off the loose paint on my 25 year old hull with my pressure washer. I WOULD NOT CONSIDER USING THIS METHOD TO GET DOWN TO THE GEL COAT. THAT LITTLE HEAD WITH THE PIN HOLE COULD PROBABLY PUT A HOLE IN YOUR BOAT! It is great to get the dirt off my painted non-skid! Happy blasting,
use enough pressure to get under those loose flakes of paint. Point wand at an angle of 150 degrees to the surface and keep it moving. Don't use the pressure head that has that pin-hole... no matter what you do! Get what you can with the pressure washer... hit the rest with a scrapper; sand; wipe down... and you are good to go. I have had good luck getting off the loose paint on my 25 year old hull with my pressure washer. I WOULD NOT CONSIDER USING THIS METHOD TO GET DOWN TO THE GEL COAT. THAT LITTLE HEAD WITH THE PIN HOLE COULD PROBABLY PUT A HOLE IN YOUR BOAT! It is great to get the dirt off my painted non-skid! Happy blasting,
don't do it
The father in law tried cleaning his pick up truck cap, which is fiberglass with a similar depth gelcoat. This was with a 1200-1500 psi washer. All was OK until he got near the windows, where the paint and the gelcoat flew off...similar results on the curves and near the back hatch. Would not risk it. all the best dave
The father in law tried cleaning his pick up truck cap, which is fiberglass with a similar depth gelcoat. This was with a 1200-1500 psi washer. All was OK until he got near the windows, where the paint and the gelcoat flew off...similar results on the curves and near the back hatch. Would not risk it. all the best dave
Most Marinas...
...will use one to pressure wash a boat's bottom when they haul it. Call a local marina to find out what pressure they use to do the job. Then just stay clear of the gelcoat! Do that part by hand with a scraper of some sort.
...will use one to pressure wash a boat's bottom when they haul it. Call a local marina to find out what pressure they use to do the job. Then just stay clear of the gelcoat! Do that part by hand with a scraper of some sort.
I would not recommend it. We use a 2000 psi
washer to clean the hull after haulout. The water is shot at an adequate distance with the appropriate nozzle setting; it taks away most of the crap leaving the paint practically untouched. The paint is removed the old fashioned way by scraping and sanding.
washer to clean the hull after haulout. The water is shot at an adequate distance with the appropriate nozzle setting; it taks away most of the crap leaving the paint practically untouched. The paint is removed the old fashioned way by scraping and sanding.
Water vs sand
I understand the warnings regarding the small aperature nozzle. I've seen one do some serious damage. On the other hand, I've seen damage done by soda/sand blasters too. I wonder if that generally more accepted process would pass muster here.
I understand the warnings regarding the small aperature nozzle. I've seen one do some serious damage. On the other hand, I've seen damage done by soda/sand blasters too. I wonder if that generally more accepted process would pass muster here.
Thanks for you advices everyone
Since I will do the bottom paint job on MY first sailboat, instead of doing on daddy's boat, I will go for big scraping job!!! One of the only times we wish to own a smaller boat!!! But I still be a little bit lazy and will use paint striper then! http://www.franmar.com/practical.html Thanks
Since I will do the bottom paint job on MY first sailboat, instead of doing on daddy's boat, I will go for big scraping job!!! One of the only times we wish to own a smaller boat!!! But I still be a little bit lazy and will use paint striper then! http://www.franmar.com/practical.html Thanks
I used to paint aircraft and used a PW to remove
stripper from aluminum. I also used the same PW on fiberglass with no issue for tip tanks, radomes etc. The key is to use the fan nozzle, keep the angle to 45* or so and watch your distance. If you're gouging gelcoat, you have other issues.
stripper from aluminum. I also used the same PW on fiberglass with no issue for tip tanks, radomes etc. The key is to use the fan nozzle, keep the angle to 45* or so and watch your distance. If you're gouging gelcoat, you have other issues.
I cant negate
Riches experience but I agree with Charlie. I own a 3500 psi 4 gpm pressure washer that i have used for everything but trying to strip bottom paint. I have pealed paint right off spots on trucks but that just meant it was a bad paint job. gel coat is going to be a lot harder then bottom paint but a good adheasion of paint will not come off readily with a power washer either. I have held mine very close trying to blow off decals from gel coat with no apparent dammage. Edit: Antonie I would think that you could blow off whatever came easily from 3 0r 4 " away and finish the rest by hand. Just dont sit there and hold it in one spot keep it moving. As far as drying time that depends on your weather. The pros say a wet impregnated glass hull can take anywher from 1 to up to 6 months to dry out. I doubt that pressure washing is going to blast much water into your fiberglass thru the jel coat, this take years to occur by ossmosis while sitting in the water. I will have to check our reg's but I dont know if we would be alowed to do that in the yards around here anyway.
Riches experience but I agree with Charlie. I own a 3500 psi 4 gpm pressure washer that i have used for everything but trying to strip bottom paint. I have pealed paint right off spots on trucks but that just meant it was a bad paint job. gel coat is going to be a lot harder then bottom paint but a good adheasion of paint will not come off readily with a power washer either. I have held mine very close trying to blow off decals from gel coat with no apparent dammage. Edit: Antonie I would think that you could blow off whatever came easily from 3 0r 4 " away and finish the rest by hand. Just dont sit there and hold it in one spot keep it moving. As far as drying time that depends on your weather. The pros say a wet impregnated glass hull can take anywher from 1 to up to 6 months to dry out. I doubt that pressure washing is going to blast much water into your fiberglass thru the jel coat, this take years to occur by ossmosis while sitting in the water. I will have to check our reg's but I dont know if we would be alowed to do that in the yards around here anyway.
as long as you contain the debris
and dont release restricted solvents into the air there's no fowl. throw down a drop cloth that water can get through but catch all the crap and dont let it flow down the street or into the water
and dont release restricted solvents into the air there's no fowl. throw down a drop cloth that water can get through but catch all the crap and dont let it flow down the street or into the water
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