Bottom Paint removal - soda blast or chemical

[Meshuggana]

I have to get off 10 years of vc17 from a fresh water bottom and prepare it for salt water. No experience with soda blasting and have read it can be a real pain if you don't know what you are doing. Not to mention I would have to close the hull in with reasonable effort and thought. I have also considered chemical removal but am afraid of damaging the gel if left on to long. In am keen on hearing other peoples experience and what brand names they used. It won't help that I have to do this in Canada at about 0 degrees C but I will have to figure that one out on my own.

Allen

[rc sail]

Good day Allen, I have been using VC17 on my boats on Lk Michigan for the last 14 years. As you know it goes on in
thin coats and wears away. I think even with a number of VC17 layers on your boat it is still going to be a thin coating of VC and sanding would be my recommendation. Another thought..I use isopropal alcohol (90%) as a thinner and clean up solvent for the VC17. Wonder if alcohol and rag would wipe off VC, similar to a chemical stripper?
There have been a couple boats in our yard that relocated to salt water and the owners had a fairly easy sanding down
the VC to barrier coat. Suggest you try a section sanding and see how much work to remove the VC. And probably want to do so with a vacumm sander The boats I have seen soda blasted have been done by professionals with the ground and hull well tented to contain residue.

[Meshuggana]

Yes VC17 is very thin, it’s also highly toxic (copper) and in dust form, can get into your lungs and eyes and even with protection will do some very nasty things. My buddy who left for the Bahamas this fall sanded his bottom to the barrier coat. He looked like Bert the chimney sweeper in Mary Poppins. He had a respirator and full face mask. He was miserable and swore he would not wish that on his worst enemy. Volatile solvents like alcohol or even acetone will only smear it and saturate rags faster than you can supply them. There must be a better way!
Allen

[stefanw]

I used a Festool Rotex 150 sander with the accompanying festool vacuum cleaner and an assortment of sanding discs when I took my 49 down to gel coat this summer, no dust either on my self or on the ground. 
Start to finish it took me about 12 hours total 

[Seagem]

I can recommend the Pro Scraper by Gelplane International. It’s basically a tugston blade in a comfortable handle that attaches to a vacuum cleaner. It’s hard physical work (will keep you warm in the cold) but it is easy to control, will not damage the hull, is environmentally friendly and all the AF is collected in the vacuum cleaner bag. They cost about £32 UK Sterling.

[vasko]

The only way that does the job without hard work is sodablas - in the end whatever you do dont forget(save miney) to put epoxy barier coat and primer - or guarantied ismisus in 2-3 years.