To strip or not

[exoduse35]

I am re finishing my mast at long last. It is in it's original white finish that is in remarkable shape considering its age. It does however have a large number of scrapes and gauges that are to the metal and a few spots where corrosion has began. The dilemma comes in deciding whether to sand it down and feather out the chips using the old paint as a primer. Or is it better to chemically strip the whole thing and start from scratch. My experience with auto finishes tells me that you can never get a better bond than the factory, but they work in steal and are set up for a much higher volume so can bake and dip and what ever to make it hold up. However the mast is a whole different animal and whatever was originally applied while holding up well may not be compatible with the best finishes available today. which I guess brings me to the questions of what is the best finish product? I have the ability to spray the product but is it going to be any better than a rolled and tipped job especially after figuring in the safety concerns involved? Thanks in advance for your replies, Edd

 

[Christian Williams]

I have limited experience, but had the same question when repainting my boom.

While sanding and filling and priming, I concluded that nothing could hold better than the remaining original factory paint. It was just bonded perfectly, and the fairing of scratches left them invisible.

As for spraying, I wished I'd sprayed the boom, because rolling and tipping with Brightside (a one-part paint) I could not get a really perfect surface (gloss black is difficult anyhow). You may well be a better roller-tipper, but I find the guesswork of thinning to make for unpredictable results on curvy surfaces like spars.

On the other hand, it takes a bosun's chair to reveal imperfections on a mast so....

 

[lnill]

I have limited experience, but had the same question when repainting my boom.

While sanding and filling and priming, I concluded that nothing could hold better than the remaining original factory paint. It was just bonded perfectly, and the fairing of scratches left them invisible.

As for spraying, I wished I'd sprayed the boom, because rolling and tipping with Brightside (a one-part paint) I could not get a really perfect surface (gloss black is difficult anyhow). You may well be a better roller-tipper, but I find the guesswork of thinning to make for unpredictable results on curvy surfaces like spars.

On the other hand, it takes a bosun's chair to reveal imperfections on a mast so....

I did my mast and boom last year. Took off all hardware and ended up chemically stripping. The boom could have been sanded but the paint on the mast was so bad that stripping was the only option (boom is always under a cover). My mast had some areas where there was fairing so had to smooth those areas out after the stripper attacked the filler.

I had had our yard spray with 2 part. But after stripping the sanding went really fast and the end result was perfect.

 

[Glyn Judson]

To strip or not to strip.

Edd, I don't know if I should add my two cents worth here or not but some years ago when on the hard in The Boat Yard here in Marine del Rey, around noon a gal came in next to my boat with her Catalina 30 mast hung in horizontal slings and the boat adjacent to that. She was there to repaint the mast and boom but she first chem. stripped them. That's nothing new but what follows is. She brushed on liberal amounts of stripper in three to four foot increments followed by SaranWrap spiraled around the treated sections, repeating the process until she'd gone the full length of both parts. Mind you, when she wound the plastic wrap, she made sure to overlap the previous turn a bit so as to end up with a mast and boom completely covered, dare I say near-hermetically sealed, in plastic wrap which kept the air from evaporating the stripper. Late the next morning she reappeared to unwind the undamaged plastic wrap along with about 99% of the old paint. That was the first and only time I'd seen such a technique used and I must say, I was duly impressed. Happy New Year, Glyn Judson, The Dawn Treader, E31 hull #55, Marina del Rey CA

 

[Mort Fligelman]

Mast Refinishing

Edd...just confirming the aforementioned concerning using the old finish for the base.......it is just fine...

FWIW...my mast was original black.....but oxidized to the point of being VERY flat black, and beyond buff and polish.....when I got the boat I tried and failed to polish.....at that time I noticed that the PO had allowed the wire halyards(!@#$%^&*) to slap against the mast and quite a bit of paint was removed down the the bare aluminum......

Being a strictly fresh water sailor I did not pay the situation any heed, as I never had aluminum corrode....but after four years in the salt water environment......forget it.......so I had the yard sand and refinish the mast and since the boom was pretty much scratched up I decided to do the same to the boom, but do the whole thing in white.......they removed all of the halyards and hardware and did a beautiful job.......the price was sinful, but I am very pleased with it...and no problems...but I am back in fresh water again.

 

[PDX]

I am re finishing my mast at long last. It is in it's original white finish that is in remarkable shape considering its age. It does however have a large number of scrapes and gauges that are to the metal and a few spots where corrosion has began. The dilemma comes in deciding whether to sand it down and feather out the chips using the old paint as a primer. Or is it better to chemically strip the whole thing and start from scratch. My experience with auto finishes tells me that you can never get a better bond than the factory, but they work in steal and are set up for a much higher volume so can bake and dip and what ever to make it hold up. However the mast is a whole different animal and whatever was originally applied while holding up well may not be compatible with the best finishes available today. which I guess brings me to the questions of what is the best finish product? I have the ability to spray the product but is it going to be any better than a rolled and tipped job especially after figuring in the safety concerns involved? Thanks in advance for your replies, Edd

If your mast finish is the original factory finish you are probably OK keeping the original paint as a base. The paint on my mast was not factory. And the mast was never anodized. After I sanded the paint off there I noticed the entire mast was peppered with little corrosion spots. These had not advanced to the point where they were bubbling any paint off yet, but I assume it would have happened eventually. I don't know what the guy who had painted the mast had done wrong, but I came away with the conclusion that prepping a raw aluminum mast for paint is something that needs to be done the right way. Refreshing an existing paint coat (that has a good original bond) is a lot easier.

 

[exoduse35]

Thank you all for the response. It kinda confirms what I thaught that you can't get better than the original bond. Glyn, I remember you posting that story when it happened and was all set to try it out until the responses said not so fast! And it was nice to not see a bunch of "carefull about putting X over Y" or spraying = DEATH posts. So onward. By the way there is a sanding party at my place and you are all envited! Edd

 

[unequaltee]

Micro Blistering

While this may not be an issue in your ” sunshine state” Edd, I Just thought i would mention something that has plagued me over the years when I have had to paint aluminium in my damp part of the world.
Although it should always be a consideration before painting, Condensation and humidity doesn’t seem to cause such a problem on glass fibre or wood, but steel and especially aluminium seem to be a bit colder somehow and so are more prone to the resulting micro blistering.
The first time I came across the problem was after painting a 25 foot new aluminium horse truck I had built. Up against a deadline, I had to paint on a cold and murky day, I also made the mistake of heating the workshop before starting with a propane gas space heater. This I learnt later to my cost, increased the already high humidity level, which, unknown to me, was invisibly condensing on the cooler aluminium as this was much cooler than the air. The end spray job looked perfect for about a month before breaking out in millions of tiny blisters. I spent over a week sanding all the paint back to bare aluminium before starting again.
Although I never made the mistake of the propane heater again, I have had similar minor issues painting aluminium on less than ideal days. Just something to be aware of.
Ian

 

[exoduse35]

thanks. I knew there was a reason that I refused to work on cold damp days!