Brass Blasting Upgrade

[sarge]

My wife and I were out "yardsale-ing" and I picked up a wall-mounted shop-vac unit with the idea of making a cyclone for the blasting cabinet.

There really is no better way for prep'ing a brass model for paint in my experience. If anything needs resoldered you'll find it, the surface gets a nice even tooth to it for the paint to "grab", the surface comes out clean of oils and flux.

However it's a huge dust generator. The media wants to escape, you need a real respirator or your teeth are gritty for days, it can be hard to see your work when the aluminium oxide gets just a little age on it and starts breaking the edges of the particles away to make even more dust, and it gets loaded with pulverised old paint and decal material.

Here's the hookup:


I modified the cabinet for a filtered inlet, then made up the hose between cabinet and the vacuum unit. Originally I put a Variac on the motor so I could dial in the negative pressure so as to pull the dust but not the media itself, but found it works just fine without.

The overall arrangement looks like this:


So much cleaner to use, you can see what you're doing, and the media is getting cleaned of the useless dust that makes it "old" and hampers its effectiveness. It actually is knocking paint off more enthusiastically as the dust and pulverised paint bits are getting cleared from the media with use.

[86TA355SR]

….

There really is no better way for prep'ing a brass model for paint in my experience. If anything needs resoldered you'll find it, the surface gets a nice even tooth to it for the paint to "grab", the surface comes out clean of oils and flux.

….

I agree with you. It works well and is simple. Nothing **** up a paint job like flux!

I follow with primer immediately and it goes into a home made drying oven - used metal mailbox with a 300W light bulb. Couple hours later the tacky paint is dry.

Nice to see this post about the cabinet/vacum. Been thinking of doing this, another idea for my new work shop. Thanks!

[up148]

Good ole Yankee ingenuity. You've made a great tool even better and keeps your shop cleaner too.

[sarge]

<lifted from a different thread>

Cannot believe how lucky I am to be able to walk into a room with a four foot brake and shear, a giant bead blast cabinet with air always on, and if I wanted it, a lathe and mill.

I'm grateful for my ability to walk into my shop and use nice tools, too. Mine not a toolroom lathe and mill, but there is a rank of good instrument shop stuff; high speed press, a mill and lathe pair of Unimats fully tooled (including some really odd stuff like indexing tables), a Swiss jeweller's shear and brake, good painting gear, ultrasonics, that blasting cabinet, all that soldering stuff and good handtools for wood and styrene.

And clamps. You can never have too many clamps!

[up148]

Yes, being lucky enough to have a dedicated space for doing any hobby makes a huge difference in productivity. I don't have the big tools like you guys, but just to have a dedicated area that you can leave parts/models/tools laying out until the next day make a big difference for me.....you jump right in modeling instead of unpacking and packing away.

I find the same thing applies in the garage when working on old cars.

[sarge]

I find the same thing applies in the garage when working on old cars.

A hobby we also share.

[Norton]

When bought our 19th century house 40 years ago, the agent drove us into the driveway and I see a small barn. My wife heads to the house and I go directly to the barn. Finally a place for my tools out of the house.
I used to work in a hospital and they were tossing incubators for premature babies. The older ones were just like modern blasting cabinets with a large window, interior lights and gloves. They were also tossing a fume hood with had a cone just about perfect to let the media out for the base. I also have a Bridgeport mill and engine lathe along with saws and presses originally for motorcycle restorations but now used mainly for train part fabrication.

Back in the day when Kodak, Xerox, and Bausch and Lomb were going full speed there were dozens of shops doing support work for them. As they began to close down so did the shops so tool auctions were monthly occurrence.

Pete

[up148]

Yes, it always feels good to repurpose an item for your needs....been doing it all my life and will continue to do it. Just because it's not made to suit your purpose, doesn't mean you can't modify it to fulfill your purpose.

First thing I would check out when looking at houses to buy was the garage........and the basements when we lived in houses with basements.....not offered in OK. But something I've learned to appreciate in homes w/o basements is the lack of floor squeaks. I hate creaky floors.

[robert.]

Have you tried this yet? I needed 2 shop vacs. One wasn’t enough to overcome my incoming air.

[sarge]

Robert I'm not understanding the question.

[robert.]

Have you used your blast cabinet with that shop vac? My cabinet did not get any clearer when i ran a small shop vac on it. I had to drill a second 2.5 hole ad a flange and hook up another vaccum. My cheap tractor supply glass beader had high volume of air incoming and one shop vac could nor handle the load.
Also i tape my door shut. Hoping to keep all dust and beads inside. You dont want the stuff in your body at all. A bit of a mess those $99. Units. I worked the snot out of mine restoring 80 year ols Harley Davidson hardware

[sarge]

I have used it and it works a treat.

The seals are decent on the hatch whilst the rest of the cabinet is tightly sealed. That vac pulls hard enough such that the gloves get pulled straight when the vac is turned on. The inlet diameter is the same as the outlet to the vac so it isn't pulling hard enough to pull the media itself out but it is pulling the dust and pulverised detritus.

[robert.]

You probably have more cfm on your vacuum. Plus less presure for blasting. Cleaning 80 year old scale/rust/parkerizing/cadium takes more presure.
Is your cabinet plastic? I have been told you can use lots of water and make it a vapor blaster.

[sarge]

I don't believe the blasting pressure has much to do with it. As far as dust, there always will be some. How much depends on the media and the stuff you're knocking off. Once all the old dust and old pulverised paint from the aluminium oxide got pulled out (in mid-air) the dust level went down noticeably. I'm not dealing with glass-beads and rust here.

Lastly, the cross-section of inlet orifice (plus whatever leakage around the hatch) compared to the exhaust has a lot to do with the flow-rate. To get the negative pressure to make this work, the inlet and leaks combined need to be smaller in cross-section.

The booth is indeed plastic, but I can't see for the life of me why I'd want a vapour blaster rather than what I have, certainly not for modelbuilding.

[robert.]

Using water stops the media from sticking into the object that you’re cleaning. A plus for many things. Probably not need on toy trains.