Soda Blasting

[Norumbega Boatworks]

Hi, Been doing some research into effecient metal finishing processes and came across soda blasting- that's right sodium bicarbonate- mixed with a little water and applied under pressure-apparently micro explosions on the surface blasted lift finishes (and other materials) resulting in a clean surface with no contamination and the only waste is the material removed. Can't find anything concerning its use on wood, becoming very common metals and that "other" material- no damage or wear. Anybody have any real life experience here>

[formerlyknownasprince]

Sounds fascinating - but, in the absence of one of these doohickies, I'll be on a water-driven sandblaster later today, cleaning up some rusty gearchange bits out of the boat.

[Figmental]

My dental hygenist does a wet soda blast as a final overall finish cleaning on my teeth every time I go. Bit messy but fast and goggles are provided.

Problems can arise when the old paint is harder than the wood underneath. It takes a attentive operator to not overcut as the harder material disappears. It's usually tough to see too.

Hey, that sounds neat, a water driven sandblaster, what's it like? Is it air mixed with the water or straight water?

[steve pilot 35]

Hi my good friends father has started doing this kind of blasting here in australia, and as you said it is great on steel, even on panel steel, you can blast timber but because of the water you will get a furry efect on timber, if you use this process you will have to sand litely after

[formerlyknownasprince]

Is it air mixed with the water or straight water?
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Mixed - it uses a water blaster and an air compressor - it has some real grunt too.

Ian

[formerlyknownasprince]

Oops - it is just water - no air. I recalled that we hooked up the air compressor last time - but that was just to inflate a flat tyre on the sand buggy

[Figmental]

I found this at ultimatewasher.com

The most effective method for removing graffiti is the sand blasting. Sand Blast attachments combine high pressure water and sand to remove graffiti, paint, baked on grease, rust and much more. Use dry silica sand, baking soda or washed and dried river sand. Place the metal probe into a sand, attach the blast head to the tip of the wand and the graffities are history.

Thanks for clueing me to this tool. It looks like a less dusty, less painfull way to sandblast parts and surfaces.

[Don Z.]

Well, you did ask for "real world" experiences...

Had the deck on the 8mR done last summer as first prep for paint. Deck is plywood with an epoxy fairing compound over the top.

It did an AWESOME job on the deck.

The operator did try it on the handrails. These handrails had all the varnish worn off (prior to my purchase) and were rather "open grained". He took his time, thought he was opening the grain more, and stopped. We could have turned the pressure down more, but they would have needed sanding anyway, so we decided that it would be cheaper (i.e. I wouldn't have to pay his blasting time) if I just sanded them anyway. Break out the Fein Detail Sander.

If I would have needed to pull a finish off the rails, I would have had him continue to blast. Because of the "explosive" reaction of the soda, you can turn down the pressure and still get good results. Bottom line: Try it, go slow, and if you're damaging the wood, stop.

FWIW, a good blaster, wanting to build his business will go about it this way. The last thing he wants is a reputation for destroying things!

[Jim Budde]

Like the others have said . slick idea, but be careful. Both soda and sand do a good job of cleaning metals and unwanted harden paints off surfaces .. but they can eat a hole right thru soft wood. Of that I have first hand experience. A friend of a friend offered soda blasting as an option to scraping my cedar sided shop. Cut thru 70 years of paint clean as a whistle .. and then clear thru the cedar siding (and I do mean clear thru!)before either one of us realized it.

[MarEng]

Have used dry soda blasting on bronze propellers for years. Takes the growth off without eroding the metal like sand or black beauty. Have also used glass micro-beads. The wet angle is interesting as the soda creates one huge dusty mess dry.

[SCHOONER SARA]

Be careful, sodium bicarbonate in water solution is high on the pH scale. Some woods may react negatively and result in damage to the lignin. Especially when it is being injected into the surface at high velocity and pressure. Makes the surface sort of furry because what holds the cellulose fibers together has been desolved.

[Norumbega Boatworks]

Thanks for the comments so far, I knew or guessed about some of the concerns, want to learn more- I think there are possibilities here. Appreciate further feedback and plan to contact a couple of folks to followup on observations/contacts. Will

[alienzdive]

My friends purchased a truck almost 10 years ago when this technology was new. It is supposedly more environmentally friendly because the soda dissolves in water into gas, leaving no by product. Sand as a by-product of blasting in boat yards and marinas causes obvious problems.

The soda is also supposed to be harmless, you can eat it apparantly. However the guys who use it wear protective overalls and the soda causes rashes, itching and bleaching of hair. It is difficult to keep out of the protective clothing because it runs/soaks/dissolves in with the water.

Sand particles after hitting the surface of the boat and blasting apart into smaller particles. A small percentage of the smaller silica particles lift off into the atmosphere causing pollution. The pollution from sand blasting trucks is considerably more than expected. This is where soda blasting is better.

Becuase soda dissolves it leaves a finish ready for painting whrere sand leaves a dusty finish.

Soda blasting is fairly expensive but is totally justified by the capital expense of the equipment.

[Katherine]

To clean my boat's hull, I've been using walnut shells. I investigated using the soda, but it wasn't recomended for wood structures and the walnuts are. Besides that, the walnuts are better for the enviornment since they just decompose to dirt.

[Paulyboy]

Car companies like BMW have used walnut shells for years to clean carbonization from pistons and cylinders.
One ,question I have regarding soda blasting would be the final polishing phase after cleaning badly burned cookware, spwecifically stainless clad.

[JimJ]

How about CO2 blasting.

http://p2library.nfesc.navy.mil/P2_Opportunity_Handbook/5_2.html

Or oatmeal

http://www.woodenboat-ubb.com/cgi-bin/UBB/ultimatebb.cgi?ubb=get_topic&f=1&t=004114&p=