Wet vs dry media blasting

[Erie Fred]

Yep I found a few but shipping adds another 6-10 on top of that. I'll try calling some blasters local to me to see if they are willing to sell individual bags.

I was concerned of that as well, wouldn't want a cloud of itchy mess like you get when sanding fiberglass, but apparently these turn into literal dust on impact so not an issue in the same way as sanding grp.
I'm sure other members have experience with this and may weigh in, but it's the only thing that makes me reluctant towards air blasting and pushing me towards considering the "300kg of wet sand" scenario of wet blasting.
Have you tried any of them?


@Erie Fred have you found the other bits apart from blast media a big issue in the past?

Not really, I did it at my farm also worked at a local garage where we did it in the lot.
One year I used 12k lbs of medium black beauty (coal bottom ash) doing large beams.
Both places are "rural" with nobody within 500' at least.

I don't think you are going to remove sealer very well BTW.
Probably blast, and then go back with a knife to remove the sealer that is still hanging on, and then blast the
area under the sealer.

 

[Misterg]

I was concerned of that as well, wouldn't want a cloud of itchy mess like you get when sanding fiberglass, but apparently these turn into literal dust on impact so not an issue in the same way as sanding grp.

I've done a little blasting with ground glass. I was surprised how little dust it generated (relatively speaking). Most of the media dropped onto the ground and I ended up bring able to recover at least 3/4 of it and sieve it to use again (I put a cheap tarp down first). The fine grade I was using handles / feels just like sand.

 

[sstefana]

Not really, I did it at my farm also worked at a local garage where we did it in the lot.
One year I used 12k lbs of medium black beauty (coal bottom ash) doing large beams.
Both places are "rural" with nobody within 500' at least.

I don't think you are going to remove sealer very well BTW.
Probably blast, and then go back with a knife to remove the sealer that is still hanging on, and then blast the
area under the sealer.

Happen to be near Milton Keynes and interested in renting out the corner of a field for a weekend?
I will go over it with a breathing and scraper, then a wire wheel, and only after blasting

I've done a little blasting with ground glass. I was surprised how little dust it generated (relatively speaking). Most of the media dropped onto the ground and I ended up bring able to recover at least 3/4 of it and sieve it to use again (I put a cheap tarp down first). The fine grade I was using handles / feels just like sand.

I ordered fine as well since I have a small setup. Your reply gives me hope for air blasting

 

[brightspark]

Happen to be near Milton Keynes and interested in renting out the corner of a field for a weekend?
I will go over it with a breathing and scraper, then a wire wheel, and only after blasting

I ordered fine as well since I have a small setup. Your reply gives me hope for air blasting

whats the cfm of your comp and what size blast nozzle are you using

 

[sstefana]

whats the cfm of your comp and what size blast nozzle are you using

I have a 150l draper with a 13.x CFM belt driven pump, and an S10 pot blaster. It came with 2mm nozzles

 

[brightspark]

I have a 150l draper with a 13.x CFM belt driven pump, and an S10 pot blaster. It came with 2mm nozzles

it will do the job but be very slow its preferable to keep a constant 90 psi pressure up without dropping otherwise it alters the ratio of media and air and gets less efficient

 

[Erie Fred]

Happen to be near Milton Keynes and interested in renting out the corner of a field for a weekend?
I will go over it with a breathing and scraper, then a wire wheel, and only after blasting

I ordered fine as well since I have a small setup. Your reply gives me hope for air blasting

Sorry, I'm all blasted out.

One thing, as mentioned up above, I have also experienced.
When blasting a car, the customer (ussually a friend, I didn't do public work)
will say "just give it a light blasting".

And when I'm done, the car now looks like a speckled trout, the little spots of visible rust
end up being 2" dia. holes, and much more rust that was under the surface of the paint.

"You blasted too hard"
No, I removed the rust, you car was much rustier than you thought.

 

[brightspark]

Sorry, I'm all blasted out.

One thing, as mentioned up above, I have also experienced.
When blasting a car, the customer (ussually a friend, I didn't do public work)
will say "just give it a light blasting".

And when I'm done, the car now looks like a speckled trout, the little spots of visible rust
end up being 2" dia. holes, and much more rust that was under the surface of the paint.

"You blasted too hard"
No, I removed the rust, you car was much rustier than you thought.

i used to get that when blasting for punters you have put holes through it i instantly put them right and showed them a thin one gallon oil can i had blasted a few times with no blow through and shut them up

 

[sstefana]

it will do the job but be very slow its preferable to keep a constant 90 psi pressure up without dropping otherwise it alters the ratio of media and air and gets less efficient

That's 90psi at the pressure pot, right? It's a cpsb100, so the pressure pot version not the siphon one.

Sorry, I'm all blasted out.

One thing, as mentioned up above, I have also experienced.
When blasting a car, the customer (ussually a friend, I didn't do public work)
will say "just give it a light blasting".

And when I'm done, the car now looks like a speckled trout, the little spots of visible rust
end up being 2" dia. holes, and much more rust that was under the surface of the paint.

"You blasted too hard"
No, I removed the rust, you car was much rustier than you thought.

Thats another concern of mine with this van in general. Before blasting I will needle scale the chassis anyway and weld it wherever it punches though.

A wise man might get another and move the bits over, but I'm more scared of the mechanics than the welding for some reason

 

[Misterg]

I'm more scared of the mechanics than the welding for some reason

Embrace the fear and do it anyway. I don't think anything is quite as soul-destroying as trying to weld up a very rusty vehicle. :-/


[Edit for clarification:] Making repairs to something otherwise sound is very satisfying, but where there's just rust everywhere you look it's crushing (see Ford Transit, MX5, etc.). Never worked on one, but from what I've seen, I suspect an old Sprinter will be similar.

 

[sstefana]

Embrace the fear and do it anyway. I don't think anything is quite as soul-destroying as trying to weld up a very rusty vehicle. :-/


[Edit for clarification:] Making repairs to something otherwise sound is very satisfying, but where there's just rust everywhere you look it's crushing (see Ford Transit, MX5, etc.). Never worked on one, but from what I've seen, I suspect an old Sprinter will be similar.

It does seem to be the case for mine. Last resort will probably be to find another chassis cab and move my internals over, but I don't have all the tools, knowledge or the room for that amplitude of project now

 

[badabec]

If this van is vital for your work, buy another one.
If this van is a project for the fun of it, buy a better project.
You are entering a long winded, expensive, world of pain.

 

[sstefana]

If this van is vital for your work, buy another one.
If this van is a project for the fun of it, buy a better project.
You are entering a long winded, expensive, world of pain.

I don't need it for work. I bought it to convert to a camper, and originally looked very well with an MOT and whatnot. Less than a year later it started to shed some of its paint and underseal and show the issues, so I was hoping to rescue it.
Unfortunately it's quite a rare one, a 4x4 sprinter chassis cab with the upgraded low range transfer box, so a direct replacement is out of the question I think.

 

[badabec]

Makes sense now. Have you the space and ability to make a rotisserie for it?
Engine, gearbox, suspension all off? The blasting medium gets absolutely everywhere. Including your belly button!

 

[sstefana]

Makes sense now. Have you the space and ability to make a rotisserie for it?
Engine, gearbox, suspension all off? The blasting medium gets absolutely everywhere. Including your belly button!

I could get it in my back garden but I would have to remove a couple small trees and build a larger gate. In front of the house there's space for it, but not much more, and definitely not for 2 of them which is why I was hoping to avoid the lift and shift onto another chassis.
I have never looked into making a rotisserie, but I know what it is from YouTube videos. I don't think I would trust my welding enough to make one.

I was hoping to mask off everything I possibly can when blasting the chassis, including the complete cab with tarps tape and whatever else, and resort to sanding and wire wheeling areas where I can't mask properly.
I anticipate mud and crud everywhere, so will implement the idea from @Agroshield and use an endoscope everywhere I can shove it hehe

 

[Misterg]

a 4x4 sprinter chassis cab

Ahh, I was thinking it was a van. Chassis cab might be a bit more manageable, and 4x4 must be worth putting a bit of effort into.

 

[badabec]

Any pictures of the vehicle?

 

[sstefana]

Ahh, I was thinking it was a van. Chassis cab might be a bit more manageable, and 4x4 must be worth putting a bit of effort into.

Truly hope so hehe

Any pictures of the vehicle?

Nothing too recent, the below are from 1-1.5 years ago or so.
I found most of the bodywork repair panels. I need to buy some gas and solid wire and learn how to weld thin steel better for the cab hehe