Winter Boat Bottom Preparation in Cold Wisconsin

[Pgutierrez]

Good morning, My Catalina 36 is 20 years old and sailed on the upper Mississippi River where winter temperatures easily go to minus 25 - 30 F. Due to my boat's age and boat bottom condition after haul out, I am considering maybe having the boat bottom soda blasted (or prepped with paint stripper) during the cold winter months. By having this done during cold months, then when warm May temperatures arrive I would paint a few layers of epoxy barrier coat followed by VC17 or similar. The boat is stored outside and has an excellent winter cover that goes down to waterline stripe. Should I have any concerns about the boat bottom being exposed to the cold after being soda blasted or paint striped? For example, soda blasting / paint stripper would be applied on a warm winter day any time December to March at 40 F or higher. Boat bottom has had multiple layers of VC 17 and I feel it is time to get the boat soda blasted, bottom re sealed with an epoxy barrier coat followed by VC 17. This work would be done on the hard. Boat would be sitting 3 - 5 months out side exposed to minimal moisture and very cold (minus 30 F is probable).
Alternatively would consider using a stripper. Anyone have experience using paint strippers in cold temperatures ? Should I be concerned about having a soda blasted or paint stripped "raw" boat bottom when boat is stored outside, and most of the winter snow getting deflected by my very excellent winter cover.
(I am sending this request to a few other sources of information such as Catalina Yachts, Pettit Paints, Jamestown Distributors for their input). Please share your experiences on cold temperature boat bottom preparation where the raw boat bottom will be exposed to very cold winter temperatures.

[Jammer]

Other side of Lake Pepin here


Regarding stripper, the methylene chloride strippers are no longer available because of their toxicity and a series of fatal accidents involving bathtub stripping. The products now on the market have been reformulated. They are more flammable, and less effective, and any previous experience people have stripping bottom paint in the winter would no longer apply.


I wouldn't strip paint in the fall and leave the boat on the hard outside over the winter here. It will get wet and be unprotected from moisture. Why not schedule the work in April so that you can apply the barrier coat the day after blasting is completed?


I have not figured out why so much VC17 is used here when there are effective, multi-season ablative paints that do not pose buildup problems.

[Pgutierrez]

Hey Jammer, yes I sail out of Pepin. The previous owner had used VC17 so I had to use VC17 type paint. I used the West Marine private label VC17, considerably cheaper and in my opinion just as good.
Yes, waiting until April is an option. Just trying to widen my options. Do you know of a contractor that does soda blasting or walnut shell blasting in the area?
Looking for references. And thanks for your response.

[rslifkin]

Originally Posted by Jammer

I have not figured out why so much VC17 is used here when there are effective, multi-season ablative paints that do not pose buildup problems.

It's incredibly common on Lake Ontario as well. I think it's common to low growth fresh water areas in general, as it's smooth and low drag and at least the VC17m variant has anti-slime stuff in it.


I can see the appeal of a smooth hard paint in areas where they work well. I've got ablative on my hull, but painted the running gear with Black Widow last winter. At haulout a couple weeks ago, the props were completely clean (both by sight and touch) before powerwashing. The rest of the running gear had a little slime, but same as when I'd cleaned a bit in the water, it wiped right off with a bare finger. Definitely easier to remove than the bit of slime on the rest of the boat. Makes sense, as the Black Widow is much smoother than Micron CSC.

[pcmm]

Ideally you want to strip the bottom in the fall so that it has all winter to "dry out" But keep in mind that up here on fresh water this is probably a once in a decade type event. Specially if you are using VC-17 the build up on VC-17 is so low that you can probably go 10-15 years without heavy build up. But most people way over paint their boat bottoms on Fresh water. I painted mine in 2016 with a single good layer of Totalboat "spartan" which is like Interlux bottomkote. and its lasted 4 years with just a few touchups in the spring where pads were or work was done. Next spring I'll repaint the bottom but that's only once every 4 years... Tip don't let them clean your bottom with a 2500+psi water blaster it removes paint unnecessarily. Use a regular household pressure washer and do it either the same day or following day (latest)

[Jammer]

Originally Posted by Pgutierrez

Do you know of a contractor that does soda blasting or walnut shell blasting in the area?

I just used this guy for my aluminum dinghy. Great work, reasonable rates. I don't know if he works on fiberglass:


https://www.jlmetalfinishing.com/


I've also used Valek Sandblasting in Medford, for a bunch of antique cast iron heating registers, again, I can't speak to whether they work on fiberglass.


Hansen's Harbor (on Pepin north of Lake City) should be able to put you in touch with someone or may possibly do that kind of work themselves. I know they're booked through the winter at this point though.

[Pgutierrez]

And 2020 was an excellent year for zebra mussels! Space between rudder post and hull is jammed full, so is the paddle wheel for speed sensor. Need to floss and pick....

[Svsumurun]

Other than the mussels ( normal FYI) looking at the pic , why would you strip it? It's looks better than 1/2 the boats in the yard in the spring going into the water .
I might put a coat on it before you launch, but from that pic I wouldn't go crazy stripping or blasting .

[pcmm]

Originally Posted by Pgutierrez

And 2020 was an excellent year for zebra mussels! Space between rudder post and hull is jammed full, so is the paddle wheel for speed sensor. Need to floss and pick....

That looks like you missed painting the space between the rudder and skeg. I only get zebras on my stainless rudder shoe and bottom of my dinghy. everything else that gets bottom paint seems to be mussel free at the end of the season

[boatpoker]

Blasting is unecessary unless you have a blister issue or unless some eejit has put VC over some other anti-fouling. One mornings light sanding with 200grit on a disc sander, put another coat of VC17 and go sailing.

[Jammer]

Originally Posted by Pgutierrez

And 2020 was an excellent year for zebra mussels!

Indeed it was, and I am still finding them. We had a large crop on the fenders attached to the dock, among other places. Unusually bad year.


I don't know much about VC17 but see blasting and redoing the barrier coat as a job to be performed only when it can be put off no longer. Once you have VC17 you're stuck using it (or equivalent products) so my advice would be to just apply another coat and go sailing and keep that up until you have adhesion problems or blisters or some other reason to start over.


The best time to blast the hull of your boat is right after someone else has bought it

[AKA-None]

Touch up the vc17, get a q tip and touch some on the paddle wheel and call it a day.