Bottom Paint sander

I am gearing up to sand off the MULTIPLE layers of bottom paint on our 1977 Willard 30/4.* April is my spring break from teaching and it looks like I'll have a little over a week to do this.* There will be two of us sanding the bottom, it has not been carefully done for many years from what I can tell.* I have one Fein random orbit*sander/vacuum setup to work with and was wondering if there is another system that folks have used. This will be my first removal repaint project.* We plan to tent the entire vessel and wear quality dust protection headgear.* Are there other sanders that maybe are not as expensive as the fein that are up to this heavy work?* I am not ready to own two feins at this point.* I have a regular Dewalt random orbit but do not think it will do the job.* I've seen some Rigid sanders that look heavy enough but am not sure.*

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Suggestions appreciated from the group.

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Keith Olive

Willard 30/4

LaConner*Washington.

A google search "bottom paint stripper" will come up with the new generation strippers. I sanded a 35' sailboat to bare a number of years ago, not again.

I have the Fesstool vacuum and 6" randon Obital sander. No fun job. Did a 49' Grand Banks. Vacuum your sander a few times a day or it will load up inside. Try buying large supply of Sanding dics as they get expensive. Next time I will go with Glass bead media.

get a price on sand blasting?

Here on the Chesapeake soda blasting has become quite popular. They will arrive in the morning, tent the bottom, blast everything off the bottom of the boat leaving pristine gel coat (if that's what was under the paint!), clean up the mess and be gone by noon. Around $35 - 40/ft.

I sanded the bottom of my 37 footer with a commercial Fein/vacuum setup owned and lent by a yard. It was about as efficient a sander as you could get -- but never again! That was an ugly, dirty, backbreaking three days of work that I am just getting too old for.

dvd

I have priced soda blasting and it is above the budget we have.* We co-own this boat with another couple.* So we are going with the sanding to* good surface to prep and paint.* I do not see going all the way to the gel coat at this time.* I am hoping for no blister issues to rear their ugly heads, but we'll see.* We also plan to re-caulk the underside of the cap rail when it gets hauled and install the new name after the proper ceremony and plying of alcohol.

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I will be taking photos throughout the project.

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Keith

how about using chemical paint stripper? no dust.

I don't know about chemical stripper.* Any suggestions?* I've seen some you tube on it but am very unfamiliar with it.

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Keith

Strippers just barely work and are a PIA.* The water based ones can at least be pressure washed off rather than scraped.

I have done a 42 sailboat and my 40 foot trawler in the last couple years with a 4 inch grinder and 4.5 inch 24 grit discs...faster than anything but you do leave marks that have to be filled or ignored.

A better setup recommended by a pro is a 7 inch grinder with a soft pad under the sanding discs.* That's what I'll use for the rest of my project...after glassing and fairing the bottom...

Keith,

I did the bottom of our 1979 37' footer during spring break in 2009. I started with chemical stripper. Did not bother with a "special boat" stripper. Just used the regular stuff from the hardware store. I was careful to rinse with water to deactivate the stripper so it did not eat into the gelcoat as I went along. We never had a problem.The purpose was to remove as much bottom paint as possible before sanding smooth for barrier coat. You will have to do some sanding if you use stripper.*

I have a 6" Fein orbital that is great at dust collection. I ended up buying a dust collar (google this) for my 4" DeWalt grinder as it went more than twice as fast as the Fein. I have a lifetime of experience of running sanders so had no problem using a high speed grinder with 36-50 grit paper. Even if you make a few divots a waterproof (not polyester) filler will fix it. I finished up with 80 grit on the Fein then barrier coated. I did tape plastic above the waterline and had plastic under the boat to catch anything the vacuum did not get.

By using the stripper then the grinder, I was able to sand like erasing a chalk board (dry erase to you youngsters) rather than having to hold the machine hard against the bottom. Same with the Fein. It may seem like a lot of work but the sanding went fast using this method.

I know you don't want to go that far but you will be so close... That's why Diane calls me Mr. Anal.

Rob

37' Sedan

a grinder over sander is a tool that will remove bottom paint 10X faster...you can eliminate the stripper stage altogether if you want.* You will be standing holding a sanding/grinding tool either way.

So many people worry about the gel coat...why?* It really doesn't do anything for the bottom anyway as has been proven by about every boat built in the 70's-90's that has lived in the water their whole life.* If you are serious about keeping the bottom nice...get serious about taking the gel coat off too just to see what is beneath. I did and opened up a huge can of worms. I NEVER (nor did the surveyor) thought that there was such delamination/lamination degradation*below the gel coat. In a 4x4 area yesterday I ripped of by hand (after starting with a chisel) hunks of roving and matt 6 (that's right I said six) layers deep...almost 1/3 of the hull thickness in that area.

So if you really care about the condition of the hull on an older boat...and the posible effects of hydrolysis...the gel coat is just in the way and offers little protection from water ingress.

And for those of you who think tapping the hull with a hammer will tell you about laminate degradation (notice how I didn't say delamination) are in the herd of sheep that needs to arrive in the year 2012 and not what surveyors have been feeding you since the 90"s.* Read literature from the composite tank and pipe industry on hydrolysis...I has me thinking metal hull again.



-- Edited by psneeld on Sunday 19th of February 2012 07:27:10 AM


-- Edited by psneeld on Sunday 19th of February 2012 07:27:52 AM

I have for sale a Festool Vacuum Sander Plus. CT 22E vacuum 5.8 Gal. and access. case. List $505. With long hose. 6" rotary-random obital model RO 150 E sander, List $ 495.. 250 sanding discs also. Rubin P24 X 50; Rubin P50 X 50, Rubin P100 X 50, Titan P180 X 100. $ 150. worth of sand-discs.

like new condition. Max 3 hours running time on unit. $ 600. plus shipping from 11946.








'

This year, just paint the bottom if you can not afford to soda blast it.

Save your pennies and have it soda blasted when you can afford it. Believe me, in the end your body will thank you.

Visit a local machine shop and have them drill and tap a 1 inch brass ball, and thread an aluminum round with matching threads. Size doesn't really matter - 1/4-20, 5/16-18, 3/8-16, whatever they have on hand. Length of the round - the handle for the brass ball - should be between 12 and 18 inches. These are not expensive and are readily available. McMaster, MSCDirect, or Grainger.

Use your new custom sounding hammer on the bottom after it is soda blasted. In ten minutes time you'll be able to recognize a blister vs. good laminate, assuming you have normal hearing.

The plying of alcohol after a bottom job is a good thing! Twice as good when adding a new name.

This advice is worth what you paid for it.

Mike
Palm Coast FL.

Thanks to everyone for their feedback and suggestions.* I looks like I will proceed with the sanding and hopefully live to boat another day.........soon.

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Thanks,

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Keith Olive

Mike wrote:
This year, just paint the bottom if you can not afford to soda blast it.

Save your pennies and have it soda blasted when you can afford it. Believe me, in the end your body will thank you.

Visit a local machine shop and have them drill and tap a 1 inch brass ball, and thread an aluminum round with matching threads. Size doesn't really matter - 1/4-20, 5/16-18, 3/8-16, whatever they have on hand. Length of the round - the handle for the brass ball - should be between 12 and 18 inches. These are not expensive and are readily available. McMaster, MSCDirect, or Grainger.

Use your new custom sounding hammer on the bottom after it is soda blasted. In ten minutes time you'll be able to recognize a blister vs. good laminate, assuming you have normal hearing.

The plying of alcohol after a bottom job is a good thing! Twice as good when adding a new name.

This advice is worth what you paid for it.

Mike
Palm Coast FL.

Click to expand...

You can hear the difference if there enough delamination but if it's just starting and or just dry....good luck.* MANY a surveyor with a tapping hammer has missed boats with poor/dry laminations.

I have tbeen tapping my hull for months and my hearing isn't that bad and I still find areas where I can pull off by hand or strip with gentle chiseling that sound out just fine.*

The only way you can tell for sure is to see the light spots after the gel is gone.

I still think stripping the gel coat off is the ticket...it's the only sure way of knowing how extensive hydrolysis is and it ISN"T doing one damn bit of good on your boat...