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Cleaning up bridgeport mill

adambomb777

Aluminum
Joined
Dec 21, 2012
Location
Newberry Springs, Ca
I just got a bridgeport mill yesterday and am starting to take it apart. I have only lubed up everything with pb blaster and tested a rust remover with 0000 steel wool. I have found some pretty good info on removing the table, so I think I can figure it out. I was wondering what the best way is to get lube under the table before I try to slide it off? Also what process would you guys use to de-rust this table? I was thinking electrolysis for the rust inside the t slot areas, but don't want to ruin anything. Any recommendations are appreciated. Let me know if the link to the pictures doesn't work.

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I just got a bridgeport mill yesterday and am starting to take it apart. I have only lubed up everything with pb blaster and tested a rust remover with 0000 steel wool. I have found some pretty good info on removing the table, so I think I can figure it out. I was wondering what the best way is to get lube under the table before I try to slide it off? Also what process would you guys use to de-rust this table? I was thinking electrolysis for the rust inside the t slot areas, but don't want to ruin anything. Any recommendations are appreciated. Let me know if the link to the pictures doesn't work.

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Pictures did not work for me.

Based on my limited experience, I would venture to guess that the area where the table has been sitting on its ways has not rusted. I'd say work on knocking down the rust on the exposed areas, then remove the gib - at that point the table can be lifted slightly to come off with no sliding whatsoever. But let me hasten to say that I'm a newbie in this area (BP and similar mills) - hopefully someone else with more experience can validate or refute the above ...
 
Pictures
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I would move the thread to http://www.practicalmachinist.com/vb/machine-reconditioning-scraping-and-inspection/

you may get more specific advice form the rebuilders. Things on that mill look needing a lot of attention. Try to pump PB into the oil fittings. Let things sit as long as you cannot easily break them loose. Remove as much rust as you can with the least amount of damage. make sure you try not brake any of the parts.

dee
;-D
 
I would move the thread to http://www.practicalmachinist.com/vb/machine-reconditioning-scraping-and-inspection/

you may get more specific advice form the rebuilders. Things on that mill look needing a lot of attention. Try to pump PB into the oil fittings. Let things sit as long as you cannot easily break them loose. Remove as much rust as you can with the least amount of damage. make sure you try not brake any of the parts.

dee
;-D
Ok, I will try to move the thread. I will definitely take my time and not force anything. Thank you.

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That's a wee bit rusty! As D said, since you've got zerks, pump some PB or other in there and let it do some work. Still, ultimately you're going to have to get after the rust you can see, remove the gib, and take the table off. T'were it me, I'd not want to crank it back and forth any before taking it apart.

What are we seeing in the second picture? If that's a close up of a bearing surface ... I'd be hoping you got this for scrap price or less!
 
I got most of the oil passages cleaned out, still waiting on some zerks to loosen up. I have not moved anything, just cleaning the exposed areas of the table way. Second picture is of the top table surface where I cleaned up a small section of the table.

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I know you don't want to hear this, but that machine is in pretty sad shape. Cleaning it up isn't going to help the ways and lead screws. Just saying thata you'll have a lot of money in that machine before you're making chips.
JR
 
I'm not to concerned if it doesn't work out. My goal is to get it running and learn how the machine works. That way if I buy one in good shape later I know how it operates and how to test accuracy. I have never used a mill, so just the learning experience is good enough for me.

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Adam that is an older mill and one thing the factory did was screw up everyone with the zerks. Those are not for grease, never were, they are for way lube but so many were pumped up with grease they blocked the flow. Bridgeport went to the 1 shot lube system and did away with them. I would just get some way lube in an oil can and lube up the lead screw under the table. Judging by the looks of it I would remove the way guards in for Y axles, unscrew the gib to see how it looks and lube up the ways. Typically the ways wear in the center from most of the use.
 
Adam that is an older mill and one thing the factory did was screw up everyone with the zerks. Those are not for grease, never were, they are for way lube but so many were pumped up with grease they blocked the flow. Bridgeport went to the 1 shot lube system and did away with them. I would just get some way lube in an oil can and lube up the lead screw under the table. Judging by the looks of it I would remove the way guards in for Y axles, unscrew the gib to see how it looks and lube up the ways. Typically the ways wear in the center from most of the use.
 
Adam that is an older mill and one thing the factory did was screw up everyone with the zerks. Those are not for grease, never were, they are for way lube but so many were pumped up with grease they blocked the flow. Bridgeport went to the 1 shot lube system and did away with them. I would just get some way lube in an oil can and lube up the lead screw under the table. Judging by the looks of it I would remove the way guards in for Y axles, unscrew the gib to see how it looks and lube up the ways. Typically the ways wear in the center from most of the use.
I have all the zerks removed and have shot pb blaster down them with an air hose. All of them seem to be flowing freely now. I will remove the gib before I take off the table. I am still waiting on the way lube from zoro, 5 to 10 days before it ships from manufacturer. Do you think I could use some 75/90 synthetic gear lube for the lead screw and sliding the table off?
 
I am trying to decide between two options for cleaning the table, electrolysis and evaporust. I have everything to do the electrolysis and the evaporust will cost me $100(container and 5 gallon jug). Will electrolysis destroy any of the materials on the mill table? It also seems like it would be pretty tough to clean the black left by electrolysis in the t slot area. What do you guys think?
 
We always used way lube and places like graingers, MSC, McMaster- Carr should stock it.

The table gib is on the LH front side of the table and is scraped part. I don't know how well it will be if there is rust on it, most likely not very good. The LH table bearing bracket is the preloaded side as well, that is why you always see a power feed on the RH end. You can remove the RH nut, handle, and dial, then the 4 socket heads from the LH bracket and unscrew the lead screw from the bronze nut. If you look under the LH side you will see the small locking screw and larger lash screw on the bronze nut and bracket. You might have to loosen them. Backlash should be 5- 007". With the lead screw out, remove the table gib, and RH bracket and slide the table on to a cart. You might be able to get at the oil grooves from there to clean out. I never had to work on a Bridgeport that was like yours, old Corvettes yes but machine tools no, they were usually kept oiled and clean. My Round overarm Bpt is about 60 years old, has slight surface rust but the ways are good, while worn in the center, they are good enough for what I use the machine for. I rebuilt the head 27 years ago and the part cost then was $2000.
 
I know you don't want to hear this, but that machine is in pretty sad shape. Cleaning it up isn't going to help the ways and lead screws. Just saying thata you'll have a lot of money in that machine before you're making chips.
JR
Not sure what you are basing this statement on. Bridgeports are designed to accept wear, with adjustable gibs, lead screws etc. No way for us to know from here if your machine is badly worn and rusty, or just rusty.

My machine was a little rusty when I got it. Maybe not as bad as yours, but definitely not well oiled. Under the rust were good scraped surfaces.

I cleaned my table with WD-40 and a green scotch brite pad. Came out looking pretty good. I would not recommend electrolysis. Read bradjacobs step pulley thread for his detailed instructions.

Also, I wouldn’t wait for the magic lube to start disassembly. Hose it down with WD40 and get to work.

I found purple power to be a effective cleaner, degreaser, that seemed to remove rust pretty effectively.

Only part of my mill that gave me any trouble was the ram. Daily doses of WD-40 for a few days running, standing it up right on the floor so the oil could run down seemed to help. After a few days, a rap with a dead blow hammer freed it up. Patience helps.

Only way to diagnose your machine is with hard numbers derived from careful inspection. We are super helpful and generally happy to speculate. But we also need to catch ourselves occasionally. We can be more helpful as you provide more data.
 
I was just over in the UK where I was shown how Citric Acid mix with water works amazing as a rust remover.
member " andrewmawson " on here and ths UK site is where he speaks of using it. He showed me his break and H Frame press he used it on and it worked slick. He explained to me other rust removers makes the rust expand as it comes off but the citric acid dissolves the rust and it shrinks. Or something like that. He had a huge bag of it and he said it is cheap. Im not sure of the ratio of it and water. hopefully he will come and tell us. Rich


http://madmodder.net/index.php/topic,10085.0.html
and http://madmodder.net/index.php/topic,8981.msg98260.html#msg98260 #23 talks about it. will let Andrew know on here and see if he can come and comment.
 
Bruce Ballen showed the use of Evaporust in an past post (2016), Used on a surface grinder with rust as bad as on your mill.
I don't think your mill is scrap. I like to flat oil stone the machined areas with the smooth side of a Norton stone with oil.
Don't wire brush you dials..but use a fine file to just smooth off the nick tops down to original surface, then with fine abrasive paper backed with a strip of business-card type parer or .020 shim stock spin the dial to just see the original surface almost clean up. This keeps the lines and number sharp edged and crisp..Brushing rounds off the edges and makes numbers hard to see..you want to just barely get down to the original surface on dials.

We used to use a fine pick and clean out the numbers and lines, then fill them with red or black to make the dials look like new..

http://www.practicalmachinist.com/v...r-chuck-324747/?highlight=rust+magnetic+chuck

Richard mentioned citric acid common in UK..you can get that at Walmart...may be as good as Evaporust (?)
https://www.walmart.com/ip/Citric-A...9212&wl11=online&wl12=152305739&wl13=&veh=sem

Brits are a little tight so naturally they would find a lower cost method that works as well..IMHO
Bruce on the other hand is German..Do it with the right stuff even if it costs more.. IMHO.
USA guys.. Go to PM and ask a question..perhaps best of the three.

Soaking the lead screws seems a good idea.
 
The advantage of Citric Acid is that the rust is converted to iron citrate, WHICH IS WATER SOLUBLE. So if tight fitting parts are being de-rusted (especially threaded fasteners) the citrate migrates back into the bulk of the solution.

Phosphoric Acid for instance forms iron phosphate which is not water soluble, and although smaller than the rust it came from is still larger than the original iron, so parts remain jammed !
 
After such rust removing a good wash with washing soda added to the wash solution, to rid the rust remove solutions. The soda leaves a fine powder that deters rusting ...Yes when dry a good oil coat help to not get new rust.

I wash / towel dry / then oil...
 








 
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