Surface prep... sandblast vs. grind?
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AGRIMAN
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Yeah, we had them to blast aout 300 mild steal parts for us one time (thought we were getting ahead), but after getting the first batch out of the oven we had dirt in the powder. We couldn't figure out where it was coming from.
We checked everything and finally figured out what was going on. Some of the sand was actually inbedded in the parts. You could not see or feel it, but once the parts got hot it would work it's way out and get under the power. That was a mess.........
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dragoneggs
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I can totally relate to your situation.
My company makes specialty fasteners out of metals and composites generally for aerospace. They are often adhesively bonded and contamination in processing is always a concern. Seems easy to avoid but when things go wrong it can be surprisingly hard to troubleshoot and find what is causing the problem. Manufacturing in clean environments is not easy but for critical applications it is a must.
IslandTractor
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Thanks Dragoneggs. Lots to review and ponder. I had never realized how extensive the possible modifications were for the simple HF blast cabinet.
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dragoneggs
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Yeah there's a few more I didn't show... the cut down the mesh rack inside and adding a couple support braces for heavy items such as old bench vises. A variable intake vent. Bending down the sill below the door to eliminate a resting spot for the media. Using Click Bond nutplates and Tee screws for quick and easy viewing glass replacement... and... still to go, leg extensions w/castors (I'm 6'2" and want it raised about six inches so I'm not as hunched over.
I'm a mod kinda guy so most of my stuff gets tweaked soon out of the box. Another case it point was adding a air/hydraulic jack to my HF 20ton press!
BukitCase
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"I'm a mod kinda guy so most of my stuff gets tweaked soon out of the box. Another case it point was adding a air/hydraulic jack to my HF 20ton press! "
Mark, I knew there was a reason we seemed to get along - my friends kid me about not owning anything I haven't modded, but when they get stuck figuring things out guess whose phone rings :laughing:
Another cyclone convert here, I have 2 of the plastic ones in service and a small steel one in (delayed) process for "grind shack" duty, plus I modded my Jet dust collector with their larger "super dust deputy" - I haven't changed a filter (or even LOOKED into either shop vac) in a few YEARS. I figure I'll KNOW when that's necessary when I DON'T have suction...
I did, however, learn one important caveat on the FIRST cyclone/shop vac - do NOT try to suck up styrofoam packing peanuts or you WILL be opening the vacuum itself
- anything that has more surface area than mass is NOT your friend here...
I've looked at the HF cabinet for a blaster, but depending on circumstance I might just use a free diesel tank I got (about 200 gallons or more) - it's an oval tank so I'd probably cut it about in half leaving upper and lower "U-shaped" halves, grating in center, top hinged with gas shocks so I could load it with a fork lift without damaging the cabinet - (I may actually LIVE long enough to get to THAT project )
Anyway, here's a few pics of the cyclones I'm using ATM; sorry for the "semi-hi-jack"... Steve
Mark, I knew there was a reason we seemed to get along - my friends kid me about not owning anything I haven't modded, but when they get stuck figuring things out guess whose phone rings :laughing:
Another cyclone convert here, I have 2 of the plastic ones in service and a small steel one in (delayed) process for "grind shack" duty, plus I modded my Jet dust collector with their larger "super dust deputy" - I haven't changed a filter (or even LOOKED into either shop vac) in a few YEARS. I figure I'll KNOW when that's necessary when I DON'T have suction...
I did, however, learn one important caveat on the FIRST cyclone/shop vac - do NOT try to suck up styrofoam packing peanuts or you WILL be opening the vacuum itself
- anything that has more surface area than mass is NOT your friend here...I've looked at the HF cabinet for a blaster, but depending on circumstance I might just use a free diesel tank I got (about 200 gallons or more) - it's an oval tank so I'd probably cut it about in half leaving upper and lower "U-shaped" halves, grating in center, top hinged with gas shocks so I could load it with a fork lift without damaging the cabinet - (I may actually LIVE long enough to get to THAT project
)Anyway, here's a few pics of the cyclones I'm using ATM; sorry for the "semi-hi-jack"... Steve
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dragoneggs
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Wow Steve.... you have a cyclone arsenal! They do perform incredibly! Thanks for the tip on the styrofoam I can see how they wouldn't work so well in the 'storm'.
Back to the blasting for welding... just one more observation. I can really tell the difference with blasting AR400 vs. mild steel! Last night I was using 60grit garnet media and it takes at least twice the time and I was still getting a blotchy finish rather than a consistent dull battleship gray. I'm assuming the hardness is the culprit. Anyone else notice this??? Wonder if coarser grit is the answer on harder materials. I suppose I could turn up the psi some as well.
Back to the blasting for welding... just one more observation. I can really tell the difference with blasting AR400 vs. mild steel! Last night I was using 60grit garnet media and it takes at least twice the time and I was still getting a blotchy finish rather than a consistent dull battleship gray. I'm assuming the hardness is the culprit. Anyone else notice this??? Wonder if coarser grit is the answer on harder materials. I suppose I could turn up the psi some as well.
BukitCase
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Not surprised on the AR plate - 'bout 12-13 years ago when I bought my 580, it had been "rode hard and put away wet" - sent it out for some of the repairs, and while it was gone I worked on the 2' bucket - PO had lost teeth and kept digging, so NONE of the 4 weld-on shanks would hold a tooth, they'd just "roll off" - I noticed the newer 2' buckets had FIVE teeth, figgered I'd upgrade/repair, so bought 5 new weld-on shanks and teeth, - my old (always hated) Crapsman 7' grinder decided to die when I put a 9" pipe wheel on it to clean out as much of the welds as possible (no plasma at that time) - Crapsman started slowing down, I got even MORE pissed so LEANED on it, working on a holiday weekend, getting dark, finally it got REAL dark as the Crapsman gasped its last -
No REAL tool stores open on a holiday, but HD had a 9" Hitachi (still got it, it's now a coin toss as to which of us is more "manly")
Finished up the tooth replace, noticed the wear strips on the bucket were semi-imaginary so called up my steel supplier and ordered 4 strips of 1/4x3"x32" AR400 - they cut from a "master plate", at that time it was plasma cut, and I didn't like the slightly rough edges on those strips 'cause I KNEW I'd find 'em with a bare arm when walking behind the hoe in a T shirt, so decided I'd just "break" the edges before I welded 'em on with 7018...
2 edges per strip, 15 amp grinder with 7" NEW disk, each EDGE of each strip took me about 30 minutes just to put a SLIGHT bevel on it.
Fast forward about 12 years and those strips have a "patina", but otherwise look like I just put 'em on...
I'm actually kinda surprised you EVER got anywhere with the blaster... Steve
No REAL tool stores open on a holiday, but HD had a 9" Hitachi (still got it, it's now a coin toss as to which of us is more "manly")
Finished up the tooth replace, noticed the wear strips on the bucket were semi-imaginary so called up my steel supplier and ordered 4 strips of 1/4x3"x32" AR400 - they cut from a "master plate", at that time it was plasma cut, and I didn't like the slightly rough edges on those strips 'cause I KNEW I'd find 'em with a bare arm when walking behind the hoe in a T shirt, so decided I'd just "break" the edges before I welded 'em on with 7018...
2 edges per strip, 15 amp grinder with 7" NEW disk, each EDGE of each strip took me about 30 minutes just to put a SLIGHT bevel on it.
Fast forward about 12 years and those strips have a "patina", but otherwise look like I just put 'em on...
I'm actually kinda surprised you EVER got anywhere with the blaster... Steve
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dragoneggs
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Well actually I probably understated the time and effort... to save embarrassment I suppose. :ashamed: :laughing: My crappy plasma cut edge (due to power reasons already discussed) on the AR400 said absolutely NO to my grinders. Sure wish I would have made a cleaner cut to begin with... :smiley_aafz:
BukitCase
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Back here
http://www.tractorbynet.com/forums/build-yourself/376766-cutting-down-back-blade-good-4.html
texasranger556 suggested using one of the HF magnetic tool holders as a guide - at the time I thought "he didn't read the part about the CURVED surface - but I "filed it away for later" - today I was making a 2.5x as thick "deck skirt" for my Cub RZT 50 (thread likely in next few days) so I thought I'd try his idea (he also has a PM45) - for straight cuts on FLAT material (up to about 14" per tool holder) I was AMAZED -
Those SPECIFIC ones have a curved channel with magnets glued inside, and they're enameled - as it works out, if you hold the nozzle of the PM45 torch up against that curve, it puts the tip less than 1/16" off the surface AND gives you that smooth enameled surface to drag on. Smoothest NON-wheelie cuts I've made in a LONG time...
When I post my deck repair thread it'll be clearer what I meant by "non-wheelie"... Steve
http://www.tractorbynet.com/forums/build-yourself/376766-cutting-down-back-blade-good-4.html
texasranger556 suggested using one of the HF magnetic tool holders as a guide - at the time I thought "he didn't read the part about the CURVED surface - but I "filed it away for later" - today I was making a 2.5x as thick "deck skirt" for my Cub RZT 50 (thread likely in next few days) so I thought I'd try his idea (he also has a PM45) - for straight cuts on FLAT material (up to about 14" per tool holder) I was AMAZED -
Those SPECIFIC ones have a curved channel with magnets glued inside, and they're enameled - as it works out, if you hold the nozzle of the PM45 torch up against that curve, it puts the tip less than 1/16" off the surface AND gives you that smooth enameled surface to drag on. Smoothest NON-wheelie cuts I've made in a LONG time...
When I post my deck repair thread it'll be clearer what I meant by "non-wheelie"... Steve
