Surface prep... sandblast vs. grind?

[Big Barn]

I wish there was a similar sand blasting facility around here. I have been all over the S East and dont think I have ever seen such a facility that would rent the baster and a place to work. Seen plenty of large blasting businesses, but no diy places.

I have one of those small blasting cabinets to glass bead small parts, I dont have the cfms to to do any big blasting projects.

We have one of those DIY blast shops that opened up two or three years ago. They had good reviews and customers seemed to like the atmosphere and experienced support.

I decided to drop in and check it out for a project I had in mind. It was located in a semi industrial part of town with the 3 or 4 dedicated parking spots in front of their shop occupied. On street parking was minimal in a neighbourhood known for hookers and drug dealers.

Since I couldn't even find a spot to park I couldn't really see a future for me there. I ordered my own blast cabinet that week.

Terry

 

[IslandTractor]

Here is a pic of my setup. Lots of mods to the HF cabinet thanks to Tacoma Company. But overall idea is portable and transferrable dust collection. The dust deputy mounted on a sealed bin above my shop vac. Welded up a light weight support frame and all on casters. Basically a pre filter before my vac. Probably worth a separate thread if folks interested but I can move this between tools. Blast cabinet, miter saw, router table, etc. I also have a dust collector (in the background) that is soft plumbed to my table saw and jointer, and with a bit of finesse, my wood planer.

If you have your answer on weld prep, why not treat us to a more detailed description of your blasting and dust collector set up. I'm intrigued. Can you recycle the media using this set up?

 

[AGRIMAN]

Powder coat to me is the worst coating as it flakes and rust forms under 'til the finish comes away is small sheets just like the old style automotive undercoatings did.

Powder coating is 90% prep. Get the prep and curing right and you will not have these sort of issue. Short change the prep or the curing cycle and it will come off.

 

[AGRIMAN]

I have a 350 lbs. pressure pot with a 200 cfm compressor, so we do most of our own blasting.

There is a local commercial blaster that runs dual 7500 cfm compressors with 5 pots that probably 3 tons each. It's not a DYI operation and there standard is $100 an hour, which it's bad when you consider how much they can blast in an hour.

The only problem is they blast at high pressure, so you have to be careful what you take them.

 

[dragoneggs]

Powder coating is 90% prep. Get the prep and curing right and you will not have these sort of issue. Short change the prep or the curing cycle and it will come off.

I agree with you here... prep is key. Cure ramp and dwell temp/time matters too.

 

[dragoneggs]

I have a 350 lbs. pressure pot with a 200 cfm compressor, so we do most of our own blasting.

There is a local commercial blaster that runs dual 7500 cfm compressors with 5 pots that probably 3 tons each. It's not a DYI operation and there standard is $100 an hour, which it's bad when you consider how much they can blast in an hour.

The only problem is they blast at high pressure, so you have to be careful what you take them.

Yikes... that is serious blast pressure and flow. :shocked: I imagine you can do some damage easily if you aren't careful.

 

[dragoneggs]

If you have your answer on weld prep, why not treat us to a more detailed description of your blasting and dust collector set up. I'm intrigued. Can you recycle the media using this set up?

IT, sorry for the delay... on a biz trip this week. Here is an overview of the blast cabinet mod and dust collector build.
First I bought an upgrade kit from The Tacoma Company. Mike and company are a small private company and were great to deal with. Mike spent time on the phone with me explaining sand blasting and what/why his upgrade kit significantly improves the HF cabinet. He has several options and the website doesn't do a bit of good for you but if you call, be prepared for a nice discussion to figure out what is best for you. Mike knows his stuff. You have to call. I will say also that there are lots of youtube videos on modding the HF blast cabinet. I thought about making a video and might still someday but I don't get paid for that like most of those that put out regular videos so unless I got something unique I leave it for others.



First thing I did is cut down the rack inside the cabinet to increase the workspace volume. Again lots of youtube vids on that. Second, I built a stand for a Rigid shop vac and purchased the 'Dust Deputy' and a sealable container to mount it on. Space is a premium in my shop so I built a rack on casters that carries the dust collection system. This plugs into the cabinet such that when I turn on/off the light in the cabinet the vac turns on... and off after a 5 second delay (to clear the line).

 

[dragoneggs]

The little Dust Deputy was a bit disappointing when I pulled it out of the box. It is tiny and expensive for the plastic molded funnel. But once in operation, it surprised me.



One thing that is changed plumbing wise is the air intake and exhaust are switched to create more logical flow in the cabinet. The back is now the exhaust and the side is now the draw.



The beauty of the system is the foot pedal control and the recycling method of the media. Instead of having to use 'tons' of media, the grit flows through the bottom and outside the cabinet as more of a gravity feed instead of the stock pick up tube. Much more efficient.

The foot pedal is more more ergonomical than the trigger squeeze on the OEM gun. The other gigantic improvement is the lighting. The OEM little fluorescent light is worthless. That has to go. The two halogen floods are super bright and provide heat and drying keeping the media from wanting to clump and clog.

 

[dragoneggs]

The other key features are the gun and the pressure regulator mounted on the unit.



The gun is designed more like a pen than a pistol this improves the flow as the media and air are more inline and along with the gravity feed vs. a pick up tube that tends to clog, means you can run the system at much lower psi. This is huge! About 40-45psi instead of 90+psi. So much easier on your compressor and duty cycle.

As I said before, this probably deserves its own thread but since this is a welding thread in a tractor forum I will end it here but definitely let me know if you have questions or comments. I made a few other mods but I will leave those alone for now. I absolutely love my set up now. Keep in mind I put three times as much money into the mod than I did the original purchase. :ashamed: but it was worth it.

 

[dragoneggs]

I just realized I didn't answer the question I think IT had on recycling the media... The media is recycled in the cabinet and the dust collection sucks the very fine dust but does not vacuum the 'good' media from the cabinet. The intake vent is adjustable and there are baffles on the intake and outtake to regulate the 'negative' pressure in the cabinet. The dust deputy 'cyclone' action causes 99.9% (and I am not exaggerating) of the dust to drop out in the upper canister before it reaches the pleated paper filter. After running this for several hours of blasting, I barely have any dust in the shop vac and the filter still looks clean.

One of the big problems with shop vacs is the filter and how fast it clogs. The Dust Deputy pre filtering system solves that problem. There are youtube videos on this as well showing the effectiveness. I was skeptical but now I am a believer.