Indoor pressure pot sandblasting

[CJK440]

Long time lurker, first time poster.

I am working on a 74 Camaro resto. Currently the car is stripped to a shell and has the quarter panels, outer wheelhouses and trunk floor off the car. I have some sections that need rust removal that is hard to get to via other methods such as window channels and other nooks and crannies (all attempts have been made to mechanically strip whatever I could). All in all I would estimate a total surface area of maybe 3' x 3'.

I have a single stage 60 gallon compressor which works good with my cabinet with periodic brakes to catch up. I also picked up a harbor freight pressure pot blaster and modified the plumbing as per peoples recommendations on this site knowing full well that it takes more air than my cabinet so will be taking many breaks. I plan to use fine coal slag from tractor supply with a proper hood and respirator of course.

The problem is there is a foot of snow outside and even if it was nice, I'm in a residential area and open blasting dust wouldn't be appreciated outside so I need to do this in my garage.

My plan is to set up the same "oxygen tent" setup I use as a spray booth using clear plastic as a roof and 4 sides and I plan run an exhaust fan out the window with an 8" flex duct drawing the exhaust air from inside the room to remove dust.

Has anybody done anything similar and have any tips or tricks?

 

[sberry]

It could be done but seems it might be easier to rig it to roll out the door. Something you can do with 8 inch duct is tooooo small. Twin window fan clears a bedroom. Good power box fan might clear a tent if it was directional and had orderly draw, the stuff is worse than paint, fine sand bounces less than hard but it gets everywhere.
Tent outside, a small area might be different than trying to run a sandblast operation. Could be done with it before anyone caught on. I have blasted outside in the winter. You dont have to pick a day with the worst weather, watch it on the tv and pick a nice spot, get all prepped, do it to it, blow the dust off and roll it back in.

 

[May Pop]

Inside it will make a large mess unless the tent is really well sealed. But it will work and lets you take your time.
When I blast outside I get all ready and do it as quickly as possible and then roll my project back into the shop. All there is is the air blast sound for a little while and I sweep up the mess.

Ron

 

[didit]

I learned my lesson a long time ago and will never sandblast indoors again. You will find it is impossible to contain the dust and not worth the time invested in the clean-up. You would be better off getting one of those portable garages or do like I did and find a steel framed, canvas walled gazebo to set up out doors. I use a homemade pressurized blaster and made a fresh air feed to my blasting hood with some pool vacuum hose and a filtered YardWorks leaf blower. It created a fresh air positive air flow that kept me cool as well. I did this during the past summer but you could do the same and pipe in fresh warm air instead.
I would use the garage space to close off in order to get some epoxy primer on the shell after blasting.
Here's a pic of my gazebo with my Model A coupe body standing on its cowl for easy access. I had the car done inside and out in a few days. The most important things to consider are a dry air supply and coating the bare steel as soon as you can.
I had a '74 Camaro that I bought new as well as a '72.

 

[sberry]

Inside it will make a large mess unless the tent is really well sealed. But it will work and lets you take your time.
When I blast outside I get all ready and do it as quickly as possible and then roll my project back into the shop. All there is is the air blast sound for a little while and I sweep up the mess.

Ron

If I could humanly do that its what I would do.

 

[Steve_P]

There is no way I'd pressure pot blast indoors. It makes a HUGE mess as said. But outdoors you're also not going to be sending dust clouds for hundreds of yards on a calm day. It's certainly less than running a leaf blower after mowing when it's been dry to clean up the edging and trimming. I live in a subdivision and have no concerns about outdoor blasting. Granted, it's pretty redneck, but ...

 

[Jswain]

You can do it and I have done it several times from hoods to side steps to random other sheets of metal. I make a large 12x12 tarp tent, cover the back, both sides and the top and leave the front open. The more you can move out of the shop the better because as said it makes a hell of a mess. Large intake/exhaust fan, good respirator and its probably not proper or healthy but it works & you will be miserable the entire time.

The tarps will contain ~95% of the media but the other 5% will be in places you didn't know existed in your garage, and everything will be covered in dust, ideally you would tarp/or remove everything in the garage as well which will speed up the cleanup

 

[CJK440]

I have used the plastic to create a spray booth in my garage to paint a number of cars and with the exhaust fan I have had good luck keeping the overspray in check.

Will the blasting dust behave different or is it a function of much more air volume from blasting that could overcome the negative pressure inside the "tent"?

I suppose I could pick up an outdoor tent or carport to help contain the dust when doing it outside....

 

[signcrafter]

I've done some blasting inside and no matter how well I tried to contain I ended up finding media all over for a very long time. That stuff has some magic to it and somehow gets all over and in all sorts of places.

 

[rsanter]

If you cannot or will not wait for the snow to go away, this is how I would approach it.
This is based on you saying that there is limited areas or limited sq ft are.

Using tarps or plastic sheeting I would create a booth in the garage, no need to be super sealed just block off the area from the majority of your stuff.

I would then plastic wrap the car, basically wrap it like a mummy.
I would leave the areas to be blasted exposed.
Using clear plastic sheeting I would create a tent around the areas to be blasted, basically a place to work. Not big enough for you, but big enough for you to put your arms in and work.
I first though is using a couple shop vacs but a leaf blower as mentioned may be better for the more CFM to evacuate the area.

Blast in short bits, this will allow the compressor to catch up and will allow the dust to settle.

 

[CJK440]

On the plus side, I did test out my pressure pot blaster with fine black diamond and wow it works great stripping ecoat like nothing and removing heavy rust scale not a whole lot slower. I inadvertently bought 3/8" fittings instead of 1/2 that I read on here to replace the harbor freight plumbing on the bottom but it seems to work great without the need to extend the legs.

Sectioning off the car and concentrating the dust to a specific area will be tough as most if not all are on edges like window channels, support brackets etc. I like the shop vac idea. Perhaps using one with the exhaust rigged outside the tent in conjunction with the exhaust fan and using the nozzle near the blasting area to collect "overspray".

 

[evintho]

I blasted the whole underside of my '54 out in the street and built a barrier around it to contain the dust. It was completely enclosed around the car but didn't have a top. I also layed a big HF tarp on the ground. Black Diamond fine media doesn't produce the amount of dust that sand does. When I finished, more than 99% of the media was contained inside the barrier.





I moved on from my modified HF blaster and bought a real blaster that is head and shoulders over the HF unit. My compressor is an I/R 80gal, 5hp single stage and I never have to wait for it to catch up.





I'll bet if you built a barrier like mine and threw clear plastic over the top, the indoor mess wouldn't be that bad.

 

[Jazz1]

set up a portable garage and do it in there with poly on the floor. In a garage you can curtain off around the car then open the large door a few inches to **** the dusty air out

 

[larry4406]

Evintho - you have very tolerant neighbors!

 

[mikegt4]

Evintho - you have very tolerant neighbors!

For sure, I have had neighbors that would have called the cops for just having that car in the driveway much less everything else.

 

[Indexmill]

Don't do it inside. Just don't.

 

[evintho]

Evintho - you have very tolerant neighbors!

I live on a cul-de-sac. Been here for 20 years. We all know each other and most of them come to me when they have car trouble.

 

[HMCFab9]

I'd pay someone else to blast it before I'd ever blast inside
(& I have the equipment to do it)
You will have sand coming out of EVERYWHERE for years if you do it inside.

Unless you live in a extremely "snooty" area, run it outside, blast it, run it back in.
(unless you live very close to your neighbor & his new Mercedes is sitting right next to where you are blasting)

I'd use regular sand. Coal slag is messy & can leave a haze in the air for a while which would piss most neighbors off.

 

[Crabman]

I think inside will be bad.

Maybe something like these outside?

https://www.harborfreight.com/10-ft-x-10-ft-portable-shed-63297.html

https://www.harborfreight.com/10-ft-x-17-ft-portable-garage-62860.html

 

[Blickus]

How about a vacuum attachment for the blast nozzle? A home brewed system here:

https://www.sandblasterinfo.com/sandblaster-manual/on-site-plans/

Commonly used in large industrial applications (my experience is blasting welds inside pressure vessels for mag particle inspection).