Project 1 from Trip. Category: Custom welded Shop tools and improvements

I've had glass bead in my blast cabinet for probably 6 months or longer, sometimes too much, sometimes not aggressive enough, but enough of a PITA to change that I dealt with it. Had a pump head repair the other day, needed walnut (badly scaled aluminum and brass parts), so I did the swap. 45 minutes of scooping, blowing, vacuuming, etc. Well, started on some other projects and neither media was aggressive enough, needed aluminum oxide or something else. Found Coal Slag from TSC for $8 a bag. Figure it'll crush down, I can screen it and have a finer grit and just dump it each time it dies.

Not wanting to keep spending 45+ minutes to swap, I decided to modify the bottom of the cabinet. Cheapie from Harbor Freight
http://www.harborfreight.com/media/c...mage_11310.jpg

Bought it a few years back from a friend for next to nothing.

The bottom of the media area tapers on 4 sides to a rectangular area (ALL pics taken with cabinet laying on it's back on a work table)

http://lh6.googleusercontent.com/-ZW...D0DC66E4F8.JPG

That little pipe does diddly squat to empty it, even with a vacuum hose on it. Pulled the pipe stub

http://lh3.googleusercontent.com/-1n...56AF76A8E1.JPG

Not much to work with. Tossed around several ideas, a cap, a trapdoor, etc. Came up with a sliding door. First thing is to cut the bottom, just above the curve, then weld a patch over the existing hole (or what's left of it) I thought about a round piece and pretty fit up, all tigged and shiny, then said 'screw it, I'll never see it and a surface patch is more than enough. I did cut the bottom of the hole out so it was U shaped and therefore wouldn't trap ANY media

http://lh4.googleusercontent.com/-zI...0196A2682E.JPG

Cut two 'runners' from 3/4x3/32(?)" angle iron. Beveled the front corners to make the door easier to get back on.

http://lh5.googleusercontent.com/-Wv...13E9F320B2.JPG

NASTY mill scale and surface. 40 grit discs and several minutes got it that cleaned up (more cleaning later). Took one or three shots, finally got the MIG dialed in nice for some downhill 18ga to 1/8" edge joints. Welded the top of the angle iron leg as well as the bottom corner (all scale cleaned up in the weld areas really well) Got some pieces cut and cleaned, 14ga (I think) sheet, some 3/32(?)" x3/4" flat and some 1x1/8" zinc coated crap I don't even know why I had.

http://lh3.googleusercontent.com/-jh...3AD61FB2E6.JPG

Burned them together nicely, the welds look cold, but there was plenty of penetration. Didn't feel the need to run the whole edge, so a few 3/4" long welds down the side, then I ground the area that would mate to the sheet steel.

http://lh6.googleusercontent.com/-Vm...B617D9830E.JPG

Lined one up with the edge of the sheet, clamped it in place on the runner and started tacking. I welded just about the whole length, skipping as I went. I don't have a shot of it, but after the first, I put a piece of 1/16" TIG rod in the channel on the left side, then clamped the right side in nice and tight. Once I had both sides, I put a piece across the bottom (back) to make sure it wouldn't go too far and welded a piece of angle for a handle

http://lh6.googleusercontent.com/-9F...28CB3BF64F.JPG

Before someone points out the gap on the front and back edges, the intent was to leave it a loose fit so not to grind the hell out of everything each time. A piece of foam (or folded paper towel) keeps the grit from running out those gaps and is easier to replace than a chewed up slide.

http://lh6.googleusercontent.com/-UU...FBE46F4EEF.JPG

You'll notice all the millscale is gone now, I knew it would be a snug fit, so I welded it up, knocked the slide out and then ground the bottoms of the runners till it was gone, which gave me just the right clearance to operate it smoothly.

I hadn't bothered cleaning out the last bits of walnut shell before I started, so I figured it was as good a test as any. Put it back in place and used an air nozzle to blow all the remaining media to the bottom, thumped the sides a few times to get everything loose, then pulled the handle.

Why the hell didn't I do this two years ago, I expect media changes will take about 5 minutes now, 10 if I do a really thorough job and wipe down the inside (I only do that when changing to FINER grit. I could care less if there's some walnut in my coal slag...)

Took a bit longer than I thought, but I learned one very very important lesson. When you have a hood with grind mode, ALWAYS CHECK IT BEFORE YOU STRIKE AN ARC!

Nice project, Trip. Yeah, it's things like your project that really make me appreciate my welder purchase. Now I can make / repair things that have constantly eaten time out of my life that I'll never get back.

I "added" a grind mode to my welding helmet but haven't used it too much. I have, however, tried to get in a habit of turning grind mode off immediately after using it.

Thanks for sharing, cheers!

Good job... Here's a tip, when adding a strip to a plate, try drilling a few holes in the strip and plug weld them rather than weld the edge for a cleaner look. Plug welds can also be ground down so they aren't noticeable.
I'm starting a new 48x24 blasting cabinet project tomorrow . I plan to use an 1 1/2" ball valve for a drain. Do you think that would work alright ? Any ideas or suggestions are welcomed.

I had a blast cab with a slider like that. It didn't work good for me. It would get jammed with abrasive. It was also so loose that it leaked glass bead all the time, too. When I cut it off, I copied the design from a real old cab where I used to work. It just had a straight walled opening at the bottom with a bar across it a few inches up. Then there was a floor plate about an inch bigger all around, with soft rubber glued on it and an eyebolt in the middle. An extension spring hooked the eyebolt to the cross bar. Super easy to dump and never leaked.

I've used glass bead, walnut shells and aluminum oxide. Never tried or even heard of coal slag. How does that compare? Is it clean? I love how aluminum comes out with a new batch of glass bead.

Quote:

---

Originally Posted by zoama585

Good job... Here's a tip, when adding a strip to a plate, try drilling a few holes in the strip and plug weld them rather than weld the edge for a cleaner look. Plug welds can also be ground down so they aren't noticeable.
I'm starting a new 48x24 blasting cabinet project tomorrow . I plan to use an 1 1/2" ball valve for a drain. Do you think that would work alright ? Any ideas or suggestions are welcomed.

---

I've done tons of plug welds, almost did them here too, but... I figured if I edge welded and it was too tight, I could bend them up a tad. This was meant to be a quick fix, if it was a more involved thing (like building from scratch) and/or visible, I'd have done it differently. I might have made a frame, milled out slots, etc. Whole world of possibilities.

I think an inch and a half ball valve would be plenty, I'd suggest making sure there are no surfaces for media to hang when you do it, fair the inside into the pipe smoothly or overhang it a bit like they did in mine. I'm guessing you meant PVC... a gate valve would probably last a lot longer, the ball valve may need to be replaced every once in a while when the grit gets sucked into the gap where the ball mates, it might get tough to open and close. A gate may wear, but it'd get sloppier rather than binding.

A future mod is going to be a piano hinge to lift the glass up to replace the plastic inside... it's a PITA now and near impossible to get it decent. Might be something to consider. I'm going to have weatherstrip on both sides of that, cabinet and glass frame, you can pick up clear plastic for those fancy gift baskets WAAAAY cheaper than anything intended for our purposes.

Quote:

---

Originally Posted by undercut

Nice project, Trip. Yeah, it's things like your project that really make me appreciate my welder purchase. Now I can make / repair things that have constantly eaten time out of my life that I'll never get back.

I "added" a grind mode to my welding helmet but haven't used it too much. I have, however, tried to get in a habit of turning grind mode off immediately after using it.

Thanks for sharing, cheers!

---

Mine is an XVwhatever Hobart that I painted (ugly flame design on a blue helmet...) 9-12 or 13 with grind mode, cheater clips, sensitivity and delay adjustments. Shade is on the outside, nice. Grind mode is on the inside... really designers?

Quote:

---

Originally Posted by Rambozo

I had a blast cab with a slider like that. It didn't work good for me. It would get jammed with abrasive. It was also so loose that it leaked glass bead all the time, too. When I cut it off, I copied the design from a real old cab where I used to work. It just had a straight walled opening at the bottom with a bar across it a few inches up. Then there was a floor plate about an inch bigger all around, with soft rubber glued on it and an eyebolt in the middle. An extension spring hooked the eyebolt to the cross bar. Super easy to dump and never leaked.

I've used glass bead, walnut shells and aluminum oxide. Never tried or even hear of coal slag. How does that compare? Is it clean? I love how aluminum comes out with a new batch of glass bead.

---

Ah, but I have a secret weapon, well, not so secret, I posted about it :) The bottom 1/4" gets two or three sheets of paper towel folded and stuffed, I plan to cut foam eventually. No abrasive on the door, it fully removes easily so I can clean the grooves as needed.

I've used just about every type of media except dry ice (planning to try if I can find a source locally for a decent enough price). I've used:

Play sand, silica sand (bad idea, I know) garnet, crushed glass, glass bead, crushed obsidian, coal slag, aluminum oxide, walnut shells, cob, plastic media, baking soda, even diatomaceous earth (don't do this... EVER, severe health hazard) steel bead, and I'm sure a few things I forgot

I run soda through a Paasche air eraser, works AMAZING for cleaning carb parts.

DE works amazing for taking gloss off of fiberglass resin, only certain types are designed for multiple coats. Bondo glass from wally world is single layer stuff. It contains wax that migrates to the surface to seal from air, as polyester resin won't cure fully if exposed to air. Now, before you think I'm nuts with a deathwish, I have a dozen or so blasters, the one I used a water feed simultaneously so no dust. Followed up with prep-all. Had I had soda on hand, I'd have much preferred that.

The obsidian was amazing stuff, cut faster than anything I've used before or after, haven't seen it in a long time though and was expensive as hell.

Coal slag cuts almost as good, leaves a rough surface, but what I'm blasting now is going to get TSC farm and implement primer and paint, so it's just what's called for. Now, it does degrade, it's designed as a non-recyclable media for things like tractor frames out on the side of a barn, but at $8 for 50lbs, I'll run it a while, sift it and store it as 'fine' and dump another bag in. I'll have to let you know how long it lasts with good cutting, it held up to a couple hours today with no observable difference. The best part, less dust than anything else (other than steel bead and plastic), no discernable cloud, didn't even think about hooking up a vac.

I got 20-40 grit slag, there's a finer one as well, haven't tried it yet, we'll see how this goes before I decide if I want aluminum oxide or glass in an intermediary grit. Trying to balance need and storage area ;)

I'm using it to take haze gray off my mill parts (yes, only those without ways or bearing surfaces) and it cuts clean through it fast.

What abrasive would you recommend for rusty cast iron exhaust manifolds that will be painted afterward ?

Quote:

---

Originally Posted by zoama585

What abrasive would you recommend for rusty cast iron exhaust manifolds that will be painted afterward ?

---

Honestly, I'm thinking the coal slag. Tell you what, I happen to have a rusty cast iron manifold off a '67 327, I'll throw it in the cabinet when I go out to the shop tomorrow and blast part of it, snap you a nice pic (will do it with a real camera if the iPhone camera doesn't show it well enough).

If not slag, I'd probably opt for something around a 70-80 aluminum oxide, blast the hell out of it, give it something like a TSP scrubbing and then hit it with some 2k* VHT unless you want to spend the money on a fancier high temp coating.

Last one I did I used that obsidian on, was for a '68 250 chevy, stripped it down to where it looked like it just came out of the casting sand.

The pieces I was running today with the slag were heavy sheet steel, probably 10ga or so, and some maybe 16-18 ga (electrical box from the mill) no distortion, but a lot of tooth left. I also ran a cast iron piece from the mill, horizontal table stop. Only thing it had issues with was the black filler they used originally, but then again I've had issues with that stuff with super strong stripper, knotted stainless wheels on a 4 1/2 inch grinder and 40 grit die grinder rolocs. I wish I could buy that stuff in the can, the stuff is damn near bullet-proof.

Oh, and I'm running my PSI up around 100-110, right around the max for several of my guns and enough over the max for one that it blew an o-ring :)

Now, here's the counter-intuitive part... you may want to go with a finer slag, the 30-60 rather than the 20-40, sand cast iron has lots of nooks and crannies, the finer abrasive, yet still with the sharp edges, will do a quick job. glass bead in the 80 range would do it, but would take a lot longer, leave a smoother finish. Whatever you ultimately use, be sure to clean it really well afterwards or you'll trap residue under the paint and create weak spots or little exploding spots when the media expands or thermal shocks. COE of glass vs iron is way different.

I'll be using two coats of POR-15 black velvet cured at 400゜f between coats... I want it to stay on. It needs a rough finish.

Oh, slag leaves a great finish for something like that, lots of tooth. Like I said, I'm using farm and implement enamel, I couldn't be happier with the surface it left for that. I'd say it's a match, but I'll still blast the manifold tomorrow and post some pics.

Zoama, quick blast today, really quick. As a measure of time relate-able to those who smoke, I lit a cig, walked to the shed and got the manifold, took a pic. I loaded it in the cabinet, flicked the ash, started blasting. The pic below is how much I blasted without the ash falling. Did that, took my hands out and flicked the ash. I'd say about a minute of blasting, maybe, probably more like 30 seconds.

Rusty enough?

http://lh5.googleusercontent.com/-0o...D9BCF2BAFB.JPG

1967 ramshorn for a 327.

http://lh4.googleusercontent.com/-wn...7C07CCB046.JPG

Still a bit in the small pits, hitting it with a finer slag or touch-up with bead will do it fine. Granted, this thing is old as hell, probably been rusting since '67.

I've blasted some smooth sheetmetal, surface comes out feeling approximately like a sheet of 320 or 400 wet-dry paper.

Thanks for the demo. I went to TSC this morning and picked up 250Lb of coal slag. I didn't work on my blast cabinet today, it was too cold and windy... maybe tomorrow will be a better day.

Quote:

---

Originally Posted by zoama585

Thanks for the demo. I went to TSC this morning and picked up 250Lb of coal slag. I didn't work on my blast cabinet today, it was too cold and windy... maybe tomorrow will be a better day.

---

Guessing 2x50lb bags :) if I had 250lbs, I'd probably just run it out by the fence rather than dealing with the cabinet... LOL

One thing I found, I ran another couple hours today, be sure you stop when you get wet air coming out (several cycles of your compressor) it turns into black smut on the metal that's a mess. Also, I cut my hose shorter (one of them) and wiggle it around. Seems the granules like to lock up in the gun. I'm going to try another one of my rigs tomorrow. I leave the hose right at the surface, takes a little longer, but jams much less sucking up a little bit vs a full load. Currently exploring methods to improve the feed. I'm still thrilled with it though.

I got 5 bags since I also have a pressure pot for big stuff. My compressor is 120 gallon and runs very cool.

Quote:

---

Originally Posted by zoama585

Good job... Here's a tip, when adding a strip to a plate, try drilling a few holes in the strip and plug weld them rather than weld the edge for a cleaner look. Plug welds can also be ground down so they aren't noticeable.
I'm starting a new 48x24 blasting cabinet project tomorrow . I plan to use an 1 1/2" ball valve for a drain. Do you think that would work alright ? Any ideas or suggestions are welcomed.

---

I think the ball valve might succumb to the grit fairly quickly. If I remember correctly, the big cabinet we had where I worked many moons ago had a tray shaped trap door for the dump; hinged with an over-center latch and weatherstripping to seal it. It was a pretty good sized opening too, probably about 4x4.

Great thought behind this, putting the slides outboard of the media. We had a sliding door in the cabinet at a former employer. BUT the door was a thin piece of metal that slid INSIDE a channel just thick enough for it. It was a pure PITA because just from use the slot would pack up with media making the door almost impossible to open without first vacuuming completely clean, (defeating the purpose) then using a hammer because the door would STILL be stuck! I'll be building a cabinet soon, and the bottom will borrow some design cues from your idea. Great job.

Quote:

---

Originally Posted by hooda

Great thought behind this, putting the slides outboard of the media. We had a sliding door in the cabinet at a former employer. BUT the door was a thin piece of metal that slid INSIDE a channel just thick enough for it. It was a pure PITA because just from use the slot would pack up with media making the door almost impossible to open without first vacuuming completely clean, (defeating the purpose) then using a hammer because the door would STILL be stuck! I'll be building a cabinet soon, and the bottom will borrow some design cues from your idea. Great job.

---

Thanks! Yes, the outboard works out great, hours of sitting there with a cup of tea and half a pack of smokes and this was the result. I thought about 6 other concepts leading up to this and the last couple hours were deciding on a slide or trap door. Having the rails out, and the slides on the slide itself rather than slides on the box and a piece of sheet sliding in means little to no crap in them. The slide also comes all the way off easily to tap out. I'll be doing a media change this weekend, got an aluminum case in and the slag will probably be too rough, so back to bead for a day. Hopefully I'll remember to get the video camera out and vid the change.

The ONE thing that I might recommend doing different would be to have it slide to the side, more clearance.

Quick update for those interested. The coal slag is wearing down, one bag lasted about 3-4 hours of blasting, lost effectiveness almost enough for me to change (going to give it a bit longer)

Changed the media 3 times today, took about 3 minutes each time and about 2 minutes cleanup, so 5 minutes to swap. Went from slag to walnut, walnut to bead, bead to slag. Yup, should have stayed with slag, but was trying the softest I could get away with.

I picked up five bags of coal slag at tsc and it's full of curved wire about 3/4" long. I've tried to sift it out but most of the wire goes through the screen. Ever seen this ?

If the wire is steel you can get a HF roller magnet and run over it as you pour it out on something? They have a roller type that isn't cheap, but you can also get small neos magnets on telescopic rods, make a comb out of a few of them and run it through as well.

It is steel wire? Was the bags intent blasting?