Home |
Search |
Today's Posts |
|
Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
|
#1
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
I got a rototiller at the dump. The motor is fine, but it wouldn't
shift gears. The "transmission" was a bitch to get apart, but I did it and found rust, as I expected. I'm undecided between pitching it and rehabbing it. Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp My feeling is that under these conditions the transmission would last a long time and perform normally, if noisily. Finally, I like to rehab machines, but I don't like to waste my time. A pic of one of the gears after HCl de-rusting and bead blasting (the teeth are about 1/4" wide): http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? Bob |
#2
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On Sun, 13 Jan 2008 19:57:28 -0500, Bob Engelhardt wrote:
Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? I'd run it as is. Worst case you're without a machine if it breaks. If you toss it now, you're out a machine regardless. All you're out is reassembly time and a few bucks worth of gear lube. The pitting is pretty fugly but, the high spots will wear off down to the point where there's enough contact to handle the load. You'll have a bit more lash in the geartrain than spec but, like you say, low duty cycle, low load. And it's low risk, it's not like you're fixing an airplane or something... When it blows, I don't think it'll be from pits on the gears. |
#3
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On 14 Jan 2008 01:11:06 GMT, Dave Hinz wrote:
On Sun, 13 Jan 2008 19:57:28 -0500, Bob Engelhardt wrote: Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? I'd run it as is. Worst case you're without a machine if it breaks. If you toss it now, you're out a machine regardless. All you're out is reassembly time and a few bucks worth of gear lube. The pitting is pretty fugly but, the high spots will wear off down to the point where there's enough contact to handle the load. You'll have a bit more lash in the geartrain than spec but, like you say, low duty cycle, low load. And it's low risk, it's not like you're fixing an airplane or something... When it blows, I don't think it'll be from pits on the gears. Give it some heavy lube and it will outlast you. Gerry :-)} London, Canada |
#4
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
I'm with Dave, an hour a year will not give you any problems. I WILL
have excessive backlash but that is not an issue on a tiller. Dave Hinz wrote: On Sun, 13 Jan 2008 19:57:28 -0500, Bob Engelhardt wrote: Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? I'd run it as is. Worst case you're without a machine if it breaks. If you toss it now, you're out a machine regardless. All you're out is reassembly time and a few bucks worth of gear lube. The pitting is pretty fugly but, the high spots will wear off down to the point where there's enough contact to handle the load. You'll have a bit more lash in the geartrain than spec but, like you say, low duty cycle, low load. And it's low risk, it's not like you're fixing an airplane or something... When it blows, I don't think it'll be from pits on the gears. |
#5
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
RoyJ wrote:
I WILL have excessive backlash... Can't your doctor do anything? ;-) -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |
#6
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Gotta start proofreading these. Blush.
Michael A. Terrell wrote: RoyJ wrote: I WILL have excessive backlash... Can't your doctor do anything? ;-) |
#7
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
RoyJ wrote:
Gotta start proofreading these. Blush. Michael A. Terrell wrote: RoyJ wrote: I WILL have excessive backlash... Can't your doctor do anything? ;-) Sometime I just can't pass up a funny typo. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |
#8
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On 2008-01-14, Dave Hinz wrote:
I'd run it as is. Worst case you're without a machine if it breaks. If you toss it now, you're out a machine regardless. All you're out is reassembly time and a few bucks worth of gear lube. The pitting is pretty fugly but, the high spots will wear off down to the point where there's enough contact to handle the load. You'll have a bit more lash in the geartrain than spec but, like you say, low duty cycle, low load. And it's low risk, it's not like you're fixing an airplane or something... When it blows, I don't think it'll be from pits on the gears. I think that something else will break before the gears. I agree with Dave. i |
#9
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
"Ignoramus24964" wrote in message ... On 2008-01-14, Dave Hinz wrote: I'd run it as is. Worst case you're without a machine if it breaks. If you toss it now, you're out a machine regardless. All you're out is reassembly time and a few bucks worth of gear lube. The pitting is pretty fugly but, the high spots will wear off down to the point where there's enough contact to handle the load. You'll have a bit more lash in the geartrain than spec but, like you say, low duty cycle, low load. And it's low risk, it's not like you're fixing an airplane or something... When it blows, I don't think it'll be from pits on the gears. I think that something else will break before the gears. I agree with Dave. i Not if the gears are heat treated. THe HCl treatment would have introduced hydrogen to the gears, making them subject to breakage (hydrogen embrittlement). They should receive a roast for a couple hours @ 375 degrees F to eliminate the hydrogen. Harold |
#10
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Harold and Susan Vordos wrote:
Not if the gears are heat treated. THe HCl treatment would have introduced hydrogen to the gears, making them subject to breakage (hydrogen embrittlement). They should receive a roast for a couple hours @ 375 degrees F to eliminate the hydrogen. Good to know! So far I've only derusted the one in the picture. I'll check them and use another process if they're heat treated. I assume that hardness is the indicator of heat treating. Thanks, Bob |
#11
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
"Bob Engelhardt" wrote in message . .. Harold and Susan Vordos wrote: Not if the gears are heat treated. THe HCl treatment would have introduced hydrogen to the gears, making them subject to breakage (hydrogen embrittlement). They should receive a roast for a couple hours @ 375 degrees F to eliminate the hydrogen. Good to know! So far I've only derusted the one in the picture. I'll check them and use another process if they're heat treated. I assume that hardness is the indicator of heat treating. Thanks, Bob That's correct, Bob. Don't overlook this process if they are, indeed, heat treated. Hydrogen embrittlement is a very real phenomenon. Bead blasting is a real good way to remove rust without further damaging hardened objects. If you don't have that option, use the HCl, just make sure you keep watch so it doesn't do further damage. It will dissolve solid material just as well as rust. Harold Harold |
#12
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On 14 Jan 2008 01:11:06 GMT, Dave Hinz wrote:
On Sun, 13 Jan 2008 19:57:28 -0500, Bob Engelhardt wrote: Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? I'd run it as is. Worst case you're without a machine if it breaks. If you toss it now, you're out a machine regardless. All you're out is reassembly time and a few bucks worth of gear lube. The pitting is pretty fugly but, the high spots will wear off down to the point where there's enough contact to handle the load. You'll have a bit more lash in the geartrain than spec but, like you say, low duty cycle, low load. And it's low risk, it's not like you're fixing an airplane or something... When it blows, I don't think it'll be from pits on the gears. I just "fixed" an elderly Milwaukee right angle Hole Hawg. Thing had the power cord amputated at the handle, the trigger switch was cracked into 2 pieces (JB Weld) and the reduction gears and bearings were rusted into an amorphous mass. Found head down in a 5 gallon bucket...under an eve. I left it soaking head down..in a bucket of diesel for a couple weeks, then hammered the gear cover off and the gears apart. All them needle bearings...mass of rust. Wire wheeled the gears until I could see the teeth again, soaked the head in PBlaster for another week, then reassembled it. Sounds like a coffee can filled with #3 granite..but since its only going to drill a few holes a year...I can live with it. I shudder to think of what Milwaulkee will want for a complete bearing package..and the armature needs a turning... so when it goes..it goes into the circular file. But I figure the tired old bitch will smooth out a little bit and then run for a few more years. Gunner |
#13
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Gunner wrote:
I just "fixed" an elderly Milwaukee right angle Hole Hawg. Thing had the power cord amputated at the handle, the trigger switch was cracked into 2 pieces (JB Weld) and the reduction gears and bearings were rusted into an amorphous mass. Found head down in a 5 gallon bucket...under an eve. I left it soaking head down..in a bucket of diesel for a couple weeks, then hammered the gear cover off and the gears apart. All them needle bearings...mass of rust. Wire wheeled the gears until I could see the teeth again, soaked the head in PBlaster for another week, then reassembled it. Sounds like a coffee can filled with #3 granite..but since its only going to drill a few holes a year...I can live with it. I shudder to think of what Milwaulkee will want for a complete bearing package..and the armature needs a turning... so when it goes..it goes into the circular file. But I figure the tired old bitch will smooth out a little bit and then run for a few more years. Gunner Gunner, have you ever used a variable DC power supply and an ink eraser to polish a worn commutator? I've done it to hundreds of vacuum cleaner motors, as well as power tools. I connect the motor to the power supply, then bring the voltage up slowly till the motor is turning, slowly. Then I use the ink eraser to polish the copper segments. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |
#14
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On Mon, 14 Jan 2008 02:40:36 -0500, "Michael A. Terrell"
wrote: Gunner wrote: I just "fixed" an elderly Milwaukee right angle Hole Hawg. Thing had the power cord amputated at the handle, the trigger switch was cracked into 2 pieces (JB Weld) and the reduction gears and bearings were rusted into an amorphous mass. Found head down in a 5 gallon bucket...under an eve. I left it soaking head down..in a bucket of diesel for a couple weeks, then hammered the gear cover off and the gears apart. All them needle bearings...mass of rust. Wire wheeled the gears until I could see the teeth again, soaked the head in PBlaster for another week, then reassembled it. Sounds like a coffee can filled with #3 granite..but since its only going to drill a few holes a year...I can live with it. I shudder to think of what Milwaulkee will want for a complete bearing package..and the armature needs a turning... so when it goes..it goes into the circular file. But I figure the tired old bitch will smooth out a little bit and then run for a few more years. Gunner Gunner, have you ever used a variable DC power supply and an ink eraser to polish a worn commutator? I've done it to hundreds of vacuum cleaner motors, as well as power tools. I connect the motor to the power supply, then bring the voltage up slowly till the motor is turning, slowly. Then I use the ink eraser to polish the copper segments. No, Ive not. Works well I take it? Gunner |
#15
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On Mon, 14 Jan 2008 01:00:49 -0800, with neither quill nor qualm,
Gunner quickly quoth: On Mon, 14 Jan 2008 02:40:36 -0500, "Michael A. Terrell" wrote: Gunner, have you ever used a variable DC power supply and an ink eraser to polish a worn commutator? I've done it to hundreds of vacuum cleaner motors, as well as power tools. I connect the motor to the power supply, then bring the voltage up slowly till the motor is turning, slowly. Then I use the ink eraser to polish the copper segments. No, Ive not. Works well I take it? If you don't have a power eraser handy, don't worry. The back end of any #2 pencil will polish that commutator just as well and nearly as quickly. Sand smooth with crocus or fine sandpaper, clean between the segments with an ice pick, then polish with the eraser. Works like a charm. That old Wilton 4x6 bandsaw locked up on me the last time I tried to use it. I guess I'll have to find a gearset for it after all. sigh --- Chaos, panic, and disorder--my work here is done. |
#16
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Gunner wrote:
On Mon, 14 Jan 2008 02:40:36 -0500, "Michael A. Terrell" wrote: Gunner, have you ever used a variable DC power supply and an ink eraser to polish a worn commutator? I've done it to hundreds of vacuum cleaner motors, as well as power tools. I connect the motor to the power supply, then bring the voltage up slowly till the motor is turning, slowly. Then I use the ink eraser to polish the copper segments. No, I've not. Works well I take it? I made $5-$10 every time I did it. The vacuum cleaner guy kept asking to see my "Armature Lathe', so he couldn't tell the difference. http://www.officedepot.com/a/products/930032/Paper-Pen-Pencil-Eraser/ is the erasers I used to use, but back then, they were only 25 cents. I used a modified Exacto knife blade to undercut the mica between the copper armature segments. Part of the point was ground down to let me hold it at a better angle, without damaging the edges of the copper segments. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |
#17
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Michael A. Terrell wrote:
Gunner wrote: I just "fixed" an elderly Milwaukee right angle Hole Hawg. Thing had the power cord amputated at the handle, the trigger switch was cracked into 2 pieces (JB Weld) and the reduction gears and bearings were rusted into an amorphous mass. Found head down in a 5 gallon bucket...under an eve. I left it soaking head down..in a bucket of diesel for a couple weeks, then hammered the gear cover off and the gears apart. All them needle bearings...mass of rust. Wire wheeled the gears until I could see the teeth again, soaked the head in PBlaster for another week, then reassembled it. Sounds like a coffee can filled with #3 granite..but since its only going to drill a few holes a year...I can live with it. I shudder to think of what Milwaulkee will want for a complete bearing package..and the armature needs a turning... so when it goes..it goes into the circular file. But I figure the tired old bitch will smooth out a little bit and then run for a few more years. Gunner Gunner, have you ever used a variable DC power supply and an ink eraser to polish a worn commutator? I've done it to hundreds of vacuum cleaner motors, as well as power tools. I connect the motor to the power supply, then bring the voltage up slowly till the motor is turning, slowly. Then I use the ink eraser to polish the copper segments. That sounds cool. Does the ink eraser just work as an abrasive, or is there some chemical action. What chemical is in an ink eraser? Best wishes, Chris |
#18
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Christopher Tidy wrote:
Michael A. Terrell wrote: Gunner, have you ever used a variable DC power supply and an ink eraser to polish a worn commutator? I've done it to hundreds of vacuum cleaner motors, as well as power tools. I connect the motor to the power supply, then bring the voltage up slowly till the motor is turning, slowly. Then I use the ink eraser to polish the copper segments. That sounds cool. Does the ink eraser just work as an abrasive, or is there some chemical action. What chemical is in an ink eraser? The ink eraser is very abrasive, compared to a normal eraser. It will even remove minor scratches from the copper. try it sometime. Most 120 VAC universal motors will run slowly on 8-14 VDC, and the eraser is under a buck. Keep the speed as low as possible, to keep from getting the eraser dust between the armature and the brushes. -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida |
#19
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Gunner wrote:
I just "fixed" an elderly Milwaukee right angle Hole Hawg. ... the reduction gears and bearings were rusted into an amorphous mass. ... All them needle bearings...mass of rust. ... Wow - you didn't rehab that drill, you resurrected it! It was dead and rotting and now it lives! And who would re-use rusted needle bearings? You're an inspiration, Gunner. I have a rusted needle bearing in this rototiller - I guess I'll re-use it. Well, maybe not. Bob |
#20
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On Mon, 14 Jan 2008 21:41:37 -0500, Bob Engelhardt
wrote: Gunner wrote: I just "fixed" an elderly Milwaukee right angle Hole Hawg. ... the reduction gears and bearings were rusted into an amorphous mass. ... All them needle bearings...mass of rust. ... Wow - you didn't rehab that drill, you resurrected it! It was dead and rotting and now it lives! And who would re-use rusted needle bearings? You're an inspiration, Gunner. I have a rusted needle bearing in this rototiller - I guess I'll re-use it. Well, maybe not. Bob Chuckle..with the PBlaster...some heat, some pressure, some vibration..the bearings will either wipe out totally and not even act as bushings..or start to turn. Ive got $0 in it. The drill was designed to hog screwtipped auger bits through headers and 2x4s and beams at slow speeds. Its a beast. Now instead of a dead piece of ****..its a noisy but running piece of ****. Good enough. I do industrial electrical among many other things. Not a lot of beams and whatnot in tilt up buildings. So if I use it 2x a year...2 holes...its... Good enough Gunner |
#21
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Dave Hinz wrote:
I'd run it as is. ... Can't do that - it's bound up with rust. Minimum of breaking it down, cleaning off REALLY heavy grease, removing rust, & reassembly. That's the time I didn't want to waste if it was a lost cause. When it blows, I don't think it'll be from pits on the gears. That seems to be the consensus, so I'm gonna do it. Thanks, Bob |
#22
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On Mon, 14 Jan 2008 21:29:50 -0500, Bob Engelhardt
wrote: Dave Hinz wrote: I'd run it as is. ... Can't do that - it's bound up with rust. Minimum of breaking it down, cleaning off REALLY heavy grease, removing rust, & reassembly. That's the time I didn't want to waste if it was a lost cause. Get it all broken down and cleaned up before you make your Final Decision. Or go buy any replacement parts. You don't want to be putting it back together and THEN find the cracked Pinkney Flange. When it blows, I don't think it'll be from pits on the gears. That seems to be the consensus, so I'm gonna do it. The gears are one thing, they'll run and bed in with each other if a bit rough if kept well greased. After the 'second break in' clean the gearbox out thoroughly and regrease. But the bearings are quite another matter - that can cause a self- destruct that wrecks the gearbox housing and lunches all the remaining good bits. Take it all apart and clean it up, then go find some replacement bearings. Don't spend a wad on ultra-precision ABEC Class 4 Zillion tailstock class bearings, just get something that works. Then put it back together and use it. -- Bruce -- |
#23
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
"Bob Engelhardt" wrote in message . .. I got a rototiller at the dump. The motor is fine, but it wouldn't shift gears. The "transmission" was a bitch to get apart, but I did it and found rust, as I expected. I'm undecided between pitching it and rehabbing it. Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp My feeling is that under these conditions the transmission would last a long time and perform normally, if noisily. Finally, I like to rehab machines, but I don't like to waste my time. A pic of one of the gears after HCl de-rusting and bead blasting (the teeth are about 1/4" wide): http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? Bob Have you tried the Electrolytic method of de-rusting? http://woodmangler.com/Derusting/ele...derusting.html http://www.stovebolt.com/techtips/ru..._derusting.htm http://www.hobartwelders.com/weldtal...?t=1737&page=1 Works great. Cheap and no acid involved. mark |
#24
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Mark Dunning wrote:
Have you tried the Electrolytic method of de-rusting? .... Yes, I have. I prefer acid: it's much faster; electrolytic leaves a really awful gunky residue; the length of the current path affects the derusting. Bob |
#25
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On 2008-01-15, Bob Engelhardt wrote:
Mark Dunning wrote: Have you tried the Electrolytic method of de-rusting? ... Yes, I have. I prefer acid: it's much faster; electrolytic leaves a really awful gunky residue; the length of the current path affects the derusting. I also prefer acid. i |
#26
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Ignoramus5390 wrote:
On 2008-01-15, Bob Engelhardt wrote: Mark Dunning wrote: Have you tried the Electrolytic method of de-rusting? ... Yes, I have. I prefer acid: it's much faster; electrolytic leaves a really awful gunky residue; the length of the current path affects the derusting. I also prefer acid. What acid do you use, Igor? I've read that the black oxide layer left by electrolytic derusting actually sucks for painting on because it has a significantly different coefficient of thermal expansion to that of the steel, causing it to flake off. But I haven't put it to the test yet. Best wishes, Chris |
#27
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On 2008-01-15, Christopher Tidy wrote:
What acid do you use, Igor? Muriatic. I have a jar with muriatic acid and I just put stuff into that jar to derust. After it is derusted, I would take the piece out, wash it with hot water, dry it quickly (I like to put small things on the electric kitchen range to boil water off, but no more). Then, after they cool, I put some oil on them to prevent further rusting. I've read that the black oxide layer left by electrolytic derusting actually sucks for painting on because it has a significantly different coefficient of thermal expansion to that of the steel, causing it to flake off. But I haven't put it to the test yet. I did not like the electrolytic derusting process, too much. Acid is more straightforward. i |
#28
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Christopher Tidy wrote:
What acid do you use, Igor? ... As Iggy said - use muriatic acid, which is a low grade hydrochloric acid (HCl). There is LOTS of info in the Google NG archives. Search RCM for "muriatic rust". Briefly: - do NOT use it in the shop. The vapors WILL rust every exposed steel surface!!! - it is not particularly dangerous, except to the eyes. And the fumes are very irritating to breathe. - after derusting, rinse very well, in HOT water, and IMMEDIATELY oil. The acid cleaned steel is very clean and will rust before your eyes unless protected. I like to use wax - I keep a gallon can of paste wax dissolved in paint thinner. I just dunk small parts & paint it on others. - the acid will dissolve aluminum and zinc (galvanizing). Bob |
#29
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
"Christopher Tidy" wrote in message ... Ignoramus5390 wrote: On 2008-01-15, Bob Engelhardt wrote: Mark Dunning wrote: Have you tried the Electrolytic method of de-rusting? ... Yes, I have. I prefer acid: it's much faster; electrolytic leaves a really awful gunky residue; the length of the current path affects the derusting. I also prefer acid. What acid do you use, Igor? I've read that the black oxide layer left by electrolytic derusting actually sucks for painting on because it has a significantly different coefficient of thermal expansion to that of the steel, causing it to flake off. But I haven't put it to the test yet. Best wishes, Chris Most of that black oxide brushes off easily with a stainless steel brush. I've only tried this once, but I tried dipping the post-electrolytic-treated pieces in HCl (dilute: common muriatic and 50% water) for a short time, to minimize the formation of salts and of hydrogen embrittlement, and it cleaned off the black oxide in a hurry. Overall, I prefer the electrolytic method now. The black oxide seems to have much less adhesion to the steel than the black oxide that forms when you use phosphoric acid. If you don't brush it off, though, I don't doubt that paint would adhere to it very poorly. -- Ed Huntress |
#30
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Ignoramus5390 wrote:
On 2008-01-15, Bob Engelhardt wrote: Mark Dunning wrote: Have you tried the Electrolytic method of de-rusting? ... Yes, I have. I prefer acid: it's much faster; electrolytic leaves a really awful gunky residue; the length of the current path affects the derusting. I also prefer acid. Also, does it dissolve the un-rusted metal too? Chris |
#31
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On 2008-01-15, Christopher Tidy wrote:
Ignoramus5390 wrote: On 2008-01-15, Bob Engelhardt wrote: Mark Dunning wrote: Have you tried the Electrolytic method of de-rusting? ... Yes, I have. I prefer acid: it's much faster; electrolytic leaves a really awful gunky residue; the length of the current path affects the derusting. I also prefer acid. Also, does it dissolve the un-rusted metal too? Chris Yes, it does, but very slowly compared to dissolving rust. Just do not forget to take the piece out in time. I tried both methods (electrolytic and acid). For smaller pieces, acid is much more straightforward. Wear eye protection etc. i |
#32
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On Jan 13, 7:57*pm, Bob Engelhardt wrote:
I got a rototiller at the dump. *The motor is fine, but it wouldn't shift gears. *The "transmission" was a bitch to get apart, but I did it and found rust, as I expected. *I'm undecided between pitching it and rehabbing it. Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp My feeling is that under these conditions the transmission would last a long time and perform normally, if noisily. Finally, I like to rehab machines, but I don't like to waste my time. A pic of one of the gears after HCl de-rusting and bead blasting (the teeth are about 1/4" wide):http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? Bob I've got an old Gravely tractor and several gearboxes for the rotary plow and rototiller attachments. The gearbox has a ring and pinion gear setup very like that in an auto rear end. About the same size as auto ring & pinion gears. Pinion runs at PTO speed which, as I recall, is at least 1,200 RPM. The pinion gears are machined steel, but the ring cears are cast iron - with no machining of the gear teeth. As long as they are kept lubricated, they work fine. Horsepower is in the 5 - 7.6 range, but they can handle more. If those cast iron gears hold up, I'm guessing yours will as well. If not, well, it's a rototiller. It's not likely to leave you stranded in downtown Birmingham. John Martin |
#33
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
John Martin wrote:
I've got an old Gravely tractor and several gearboxes for the rotary plow and rototiller attachments. ... Hey, me too. A couple of years ago I cleaned out my shed of a bunch of Gravely stuff that "I might need". Parted out a tractor, or 2. Whenever I put a wrench to one of those machines, I'm impressed. Built to last and they do. The pinion gears are machined steel, but the ring cears are cast iron - with no machining of the gear teeth. ... That I haven't seen. Every Gravely gear that I've seen had machined teeth. Bob |
#34
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On Jan 14, 9:55*pm, Bob Engelhardt wrote:
John Martin wrote: I've got an old Gravely tractor and several gearboxes for the rotary plow and rototiller attachments. *... Hey, me too. *A couple of years ago I cleaned out my shed of a bunch of Gravely stuff that "I might need". *Parted out a tractor, or 2. Whenever I put a wrench to one of those machines, I'm impressed. *Built to last and they do. The pinion gears are machined steel, but the ring cears are cast iron - with no machining of the gear teeth. *... That I haven't seen. *Every Gravely gear that I've seen had machined teeth. Bob The only non-machined Gravely gear I've seen is that large ring gear in the rotary plow/tiller banjo housing. Normally the machining is pretty good on their parts, and they do last. They are impressive. Used mine this morning to clear 15" of snow off the driveway with the plow blade. Plenty of power, and runs out of traction first. Think I'll try to find a set of dual wheel adapters. John Martin |
#35
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
I think the pitting will significantly increase gear noise but won't
significantly change anything else. I might try some hi-tech moly grease since it's in a gear case. Grant Bob Engelhardt wrote: I got a rototiller at the dump. The motor is fine, but it wouldn't shift gears. The "transmission" was a bitch to get apart, but I did it and found rust, as I expected. I'm undecided between pitching it and rehabbing it. Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp My feeling is that under these conditions the transmission would last a long time and perform normally, if noisily. Finally, I like to rehab machines, but I don't like to waste my time. A pic of one of the gears after HCl de-rusting and bead blasting (the teeth are about 1/4" wide): http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? Bob -- Posted via a free Usenet account from http://www.teranews.com |
#36
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On Jan 13, 4:57 pm, Bob Engelhardt wrote:
I got a rototiller at the dump. The motor is fine, but it wouldn't shift gears. The "transmission" was a bitch to get apart, but I did it and found rust, as I expected. I'm undecided between pitching it and rehabbing it. Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp My feeling is that under these conditions the transmission would last a long time and perform normally, if noisily. Finally, I like to rehab machines, but I don't like to waste my time. A pic of one of the gears after HCl de-rusting and bead blasting (the teeth are about 1/4" wide):http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? Bob By the picture, there appears to be pitting only on the non-pressure side of the gears. The tiller only works in one direction, so the pit- to-pit side of the teeth will probably never actually get together. The old cast gears were never made to mesh like machine cut gears. I would reassemble it, fill with heavy gear lube and be sure there is a vent on top so the hot oil vapors can escape. Go for it! Paul |
#37
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
|
#38
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
Bob Engelhardt wrote:
I got a rototiller at the dump. The motor is fine, but it wouldn't shift gears. The "transmission" was a bitch to get apart, but I did it and found rust, as I expected. I'm undecided between pitching it and rehabbing it. I reassembled a "gear within" hydraulic pump showing a little bit less pitting than that, and it works just fine. You should be okay. Best wishes, Chris |
#39
Posted to rec.crafts.metalworking
|
|||
|
|||
Rusted gears usable?
On Sun, 13 Jan 2008 19:57:28 -0500, Bob Engelhardt
wrote: I got a rototiller at the dump. The motor is fine, but it wouldn't shift gears. The "transmission" was a bitch to get apart, but I did it and found rust, as I expected. I'm undecided between pitching it and rehabbing it. Even with the rust removed, the gears will be very rough and wear quickly, but: - it would get very little use (maybe an hour or two per year) - the transmission runs at fairly low speed (900 rpm max input, down to maybe 50 rpm on the wheels) - it only handles 5 hp My feeling is that under these conditions the transmission would last a long time and perform normally, if noisily. Finally, I like to rehab machines, but I don't like to waste my time. A pic of one of the gears after HCl de-rusting and bead blasting (the teeth are about 1/4" wide): http://home.comcast.net/~bobengelhardt/RustedGear.jpg Waddaya think? Bob With some REAL GOOD lubricant no reason they won't work for a few hundred hours, an hour at a time. I've seen worse, and what's to loose? A few hours of work and a pint of lube? -- Posted via a free Usenet account from http://www.teranews.com |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Old Stains Still Usable? | Woodworking | |||
Swap? Atlas 10F change gears, need 618 gears | Metalworking | |||
Wooden gears to metal gears. | Metalworking | |||
Desoldering *usable* plumbing fittings | Metalworking | |||
moldy apple wood, usable? | Woodworking |