Blasting off boats - antifouling, bilges etc - CO2 Dry Ice?

[FullCircle]

I was recently in one of my suppliers who was using a portable dry ice blasting lance machine to clean his tool platens every hour or so.
As there is no moisture, and the gas just vents, it seemed a good idea for removing antifouling on boats, not to mention surface grime from topsides.
However, it can be far more intricate than that, and can be used in a variety of different applications such as removing rust from engine blocks, staining from bilges. It will even do car dash plastics and round switchgear.
There is also an application for cleaning graffiti from bricks.
I wonder if you could clean cabin sole boards and other woodwork too?

Does anyone know if this is being used anyhwere in the UK?

Anyway, here is a video of some of the applications.

 

[FWB]

Impressive.

 

[Davegriff]

Looks good. But surely risk of suffocation used in confined spaces?

 

[Spi D]

Plenty on Youtube

 

[PCUK]

Looks very slow on large areas but great for small stuff.

 

[Twister_Ken]

Greenhouse gas, anyone?

 

[Stork_III]

Greenhouse gas, anyone?

The dry ice is produce from liquid CO2 which is produced from a waste Co2. So it would be in the atmosphere anyway, just serves another purpose on the way.

 

[vyv_cox]

It's a very useful technique when the substrate needs to be left intact undamaged. Have seen it used for gas and steam turbine blades that have extremely expensive coating systems. Yards are said to allow it when they would not allow grit blasting, thanks to the cleanness of the operation.

 

[Pasarell]

As said by others it is a nice way to clean small areas but painfully slow for a whole boat. In the videos it looks as though they are only removing a single coat of antifouling. Multiple coats as most of us have would be much slower.
Some shipyards use dry ice to clean chalk marks off shop primer before painting. Ideal where they don't want a load of abrasive waste to clean out and they don't want the primer damaged.

 

[JumbleDuck]

The dry ice is produce from liquid CO2 which is produced from a waste Co2.

... much of it from the brewing industry, I believe.

 

[bikedaft]

saw a boat in sandpoint boatyard in dumbarton this year having it done. it was clean, tho v noisy. left a fair bit of old a/f on the grp tho. was expensive too tho cannot remember the (rought) quote for our boat

 

[Graham_Wright]

The dry ice is produce from liquid CO2 which is produced from a waste Co2. So it would be in the atmosphere anyway, just serves another purpose on the way.

I thought there was no liquid phase?

 

[JumbleDuck]

I thought there was no liquid phase?

At atmospheric pressure there isn't, but at anything above 5.1 bar it goes solid -> liquid -> gas. CO2 fire extinguishers have liquid CO2 in them.

 

[DanTribe]

I have used the dry ice system for cleaning parts of heritage buildings. Conservation officers don't normally allow any form of grit blasting.
It is very slow and very very expensive and only usually justifiable for fine mouldings and details.
An alternative could be soda blasting, not so aggressive as grit and the clean up is easier.

 

[savageseadog]

... much of it from the brewing industry, I believe.

And that CO2 is merely being released from sugars and starches locked up from atmosheric CO2 by plants

 

[Elessar]

I have used the dry ice system for cleaning parts of heritage buildings. Conservation officers don't normally allow any form of grit blasting.
It is very slow and very very expensive and only usually justifiable for fine mouldings and details.
An alternative could be soda blasting, not so aggressive as grit and the clean up is easier.

Clean up easier with soda ? You are joking! Leaves a film of Antifoul for 3 streets if you are not careful.

Dry ice is good but expensive because:

Buy 25kg today and there is 17kg left tomorrow. You can't keep it in stock as it melts quickly and it's difficult to plan boat blasting in advance. Weather, boat availability and variability of time taken means diaries are constantly changing.

It is also VERY slow on thick antifoul, using a lot of material.

It is no good for keels as it doesn't remove rust. So you need both, and still have to clear up grit.

But it is gentle and you can go right over the water line as it doesn't touch the gel. The only spoils are the paint itself. And you can remove vinyl graphics, stripes etc with it without gel damage.

 

[sarabande]

what about the anti-fouling residue ? That is still a classified waste, but should be a lot easier to clear up with the absence of e.g. water, soda particles etc. If used in the cabin, the gas stream will send varnish and other particles everywhere unless the area is cordoned off.

 

[Graham_Wright]

At atmospheric pressure there isn't, but at anything above 5.1 bar it goes solid -> liquid -> gas. CO2 fire extinguishers have liquid CO2 in them.

I never knew that - thanks.

 

[AntarcticPilot]

I'm planning on removing the antfouling from Capricious next year, to apply Coppercoat. Getting the job done commercially is out of our budget, but I have plenty of time! Obviously I could just go with scrapers, sandpaper and elbow-grease! But I am thinking of hiring a system like this (http://www.brandontoolhire.co.uk/en/cleaning/83-grit-blast-kit.html), along with a suitable powerwasher. I'd use soda on the hull and sand on the cast-iron keel. Has anyone any experience of using this sort of kit? Comments welcome about ease of use, efficiency and how long it takes.

 

[rogerthebodger]

Don't use sand on your cast iron keel use grit it gives a much better (rougher) surface that holds the epoxy paint primer better.