soda blasting

[memory maker 4]

i have been hearing a lot bout soda blasting... im considering doing my 23 ftrs bottom.. i just have a couple of questions...

ho much soda sould i expect to use.i have severl coats of bottom paint.
also is it possible to re gel coat or awlgrip the bottom?

thanks...

[clt_capt]

I can't give you figures on the amount of soda uses, but typically after soda blasting, you should apply barriercoat (Interprotect 2000 for example)to seal the gelcoat below the waterline - You need multiple coats - 3 to 6 typically, then you can apply bottom paint.

[jawz12]

blasting:

amount of blasting media required,is gonna be related to how much paint's on the bottom...
regel coating the blasted surfaces: it's possible,that when the paint's removed,those surfaces can be sanded,then wet sanded and buffed - that's something you will not know till the blasting's done.otherwise,spraying gel coat on,then wet sanding and buffing is gonna be a huge job...
awlgrip:awlgrip isn't designed to be "wet",as in,if you leave the boat in the water - there's gonna be a problem with the paint...

[memory maker 4]

thanks for the info, i think im going to just soda blast, then coat with a protective coating , then put on a light coat of bottom paint.. i dont leave the boat in the water for more then a few days at a time its mostly on my trailer..

[billschwabe]

I hate to muddy the waters but this is straight from the Interliux Rep; "Do NOT soda boast and go back with bottom paint". He said Soda blasting doesn't leave enough "profile" (abraded surface) for good adhesion of bottom paint or primer and leaves more of a polished finish. They want a sanding profile of 80 grit or less before applying primer or bottom paint. I know the sode blasting sounds "eco" and makes a lot less mess than regular sandblasting but if you want it to stick, sandblast, prime with 2000, them put on two coats of bottom paint.

[rraabb1]

Do you have a soda blasting outfit? I don't think you can soda blast from a typical sand blasting outfit. You might want to check on this. Soda blasting does a good job without destroying the gel coat. But you should wash with soap and water and then sand with 80 grit before applying the proper sealer. if you are going to paint the bottom, do it just like the paint manufacturer says. you may regret it if you don't. You need at least two coats of barrier coat for it to work as advertised. Otherwise you are just wasting your money. just one coat of bottom paint is also a waste of money. It will be gone or dead so fast it will surprise you. Go ahead and put two coats of bottom paint, even if you keep your boat in the water very little. This is from someone who has been doing this a long time.

[jawz12]

the above is correct - concerning adhesion

after blasting,be it sand,or baking soda - the surfaces still need to be sanded clean - i like solvent washing,prior to barrier coating.
as far as barrier coating is concerned - it's recomended to make the barrier 10mil thick - use a matchbook cover a s a guide.i use both colors of interprotect - white and grey - alternate colors - this assures a complete even coverage
i use the "tell coat method",meaning,if the boat's gonna get painted in antifouling paint - i use a single coat of a cheap hard antifouling paint,a different color than the finsh color - if the finish color is black,i use blue as the tell coat.after the tell coat's on,i roll out 3-5 coats of ablative antifouling paint - i like micron CSC,it's a multiseason use paint...when the tell coat shows,it's time to repaint in ablative.you should get 1 season per coat,depending on use...