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Considerations for building up a rusted way

Zeus1050

Aluminum
Joined
Jan 25, 2009
Location
Melbourne
I have a unique situation, I have an older small Fadal which had synthetic coolant in it and tackified way lube along with a broken lube line. Synthetic coolant is really good at turning Vactra into sticky goo , this coupled with a broken lube line and the coolant getting trapped under the turcite caused the rear X axis way to rust.The damage amounts to deep(maybe .012-.015)pockets etched in the way. Im in Florida , and we have giant mouses and lots of oranges, but no way grinder, as regrinding the way is the right way to fix this.
So, question, would it be possible to fill the pockets with silver solder? I could them scrape the silver flat and have a flat way again. It would seem that the silver could be done in dime size ares. Would heating the casting cause cracks or induce any stress? The rust could be etched out with citric acid and the surface to be repaired sand blasted? Suggestions , input pro or con?
I have also considered epoxy like Devcon or JB Weld, I have some reservations about it staying adhered at such a small thickness.
All and any suggestions appreciated. I know similar situations has come up before . Thanks
 
I have a unique situation, I have an older small Fadal which had synthetic coolant in it and tackified way lube along with a broken lube line. Synthetic coolant is really good at turning Vactra into sticky goo , this coupled with a broken lube line and the coolant getting trapped under the turcite caused the rear X axis way to rust.The damage amounts to deep(maybe .012-.015)pockets etched in the way. Im in Florida , and we have giant mouses and lots of oranges, but no way grinder, as regrinding the way is the right way to fix this.
So, question, would it be possible to fill the pockets with silver solder? I could them scrape the silver flat and have a flat way again. It would seem that the silver could be done in dime size ares. Would heating the casting cause cracks or induce any stress? The rust could be etched out with citric acid and the surface to be repaired sand blasted? Suggestions , input pro or con?
I have also considered epoxy like Devcon or JB Weld, I have some reservations about it staying adhered at such a small thickness.
All and any suggestions appreciated. I know similar situations has come up before . Thanks

If you have at least 50% surface contact, clean all the crap out of it and run it till a better machine comes along.

And by cleaning, I mean take it apart, and flush the lube lines, give it new oilers, bearings where necesseary, etc. I dont think it's worth fixing properly (and nobody is going to buy a machine with random filler in the ways), but it can likely limp along long enough to make you enough money to buy one in better condition.
 
Thats exactly what is being done, all new lube lines and units, screws reballed, turcite recut. I already have it apart and if it can be filled, it would make me feel better...Its a 1992 Fadal 20, its value is what it can make,so far I have $400 in parts invested, it was still making good parts before I tore it down. It's what I have now and Id like to see it reliable as it can be.
 
Silver solder is very soft compared to your existing ways. It's not going to hold up to any use. Any soft material you put down in the ways will hold chips or abrasives and tear up the turcite slides.

I'd be very hesitant of heating the ways to anything above about 600f, which is half what you need for silver solder. Above that you will start softening surrounding areas and inducing significant stress in the casting.

It's a commodity machine, patch it up, and plan on replacing it asap.
 
I would consider Moglice or something equivalent.
For the prepping, rather than sandblasting (which could negatively affect areas next to the pit, I would clean, deepen and rough-up the pits with a carbide bur.
Pour a few drops of Moglice to fill slightly above the surface of the way, and plane, sand, scrape it flat and level after curing.

Caveat: I have never done it, but this what I would do, in order to pull an extra mile or two from the machine.

Also, regarding rust removal, I personally prefer scraping the rust off (it works fairly well also with hardened ways), since it will show clearly where all the pits are (i.e. areas still with rust). I would remove the remaining rust only after fixing all the pits you intend to fill. Personally, I'd use Evaporust, instead of citric acid or vinegar, since the former stops once it finds non-oxidized iron and the latter would corrode also areas without rust.

Paolo
 
Moglice is about as hard as Waylock epoxy,and I would have the same reservations about it sticking as any other epoxy. Grinding deep gouges in a way is not something I want to do, while a Fadal may be considered a "commodity" machine, this one has a 99.9 % uptime since 1996,it has run 20 hours a day for months balls to the walls. Truthfully it cuts mostly aluminum and plastic, I make small runs, tooling, prototypes, it doesnt have to be fast. While sliver solder( and it could be brass or bronze rod) isnt as hard as the original way, it is harder then any epoxy and the turcite that rides on it. Issue being can the casting take the heat to apply it.
 
A moderate middle ground may be to file down a brass or silver solder rod and use those filings mixed into an epoxy to fill the holes.
 
Before you try grinding the rust out, I've had very good luck on precision surfaces with a brass bristle brush and WD-40. The combination works surprisingly well for the removal of surface rust. The brush seems to be stronger than the rust, but softer than the steel/cast surface. I'm not sure how well it would work down in a pocket, though.
 
For brass/bronze brazing or high hardness silver soldering you are going to have to get the ways red hot. I doubt you want to do that.
How about getting someone to tig braze them full of silicon bronze? they will still get hot but in a much more localized fashion.

I am not sure it is any better from a distortion point of view, but it seems like it might be the best option if you are dead set on doing something like this.
 
For brass/bronze brazing or high hardness silver soldering you are going to have to get the ways red hot. I doubt you want to do that.
How about getting someone to tig braze them full of silicon bronze? they will still get hot but in a much more localized fashion.

I am not sure it is any better from a distortion point of view, but it seems like it might be the best option if you are dead set on doing something like this.

The "best" option, as far as full adhesion and low adjacent/overall stress, before, during, and after appplication - is probably not even close to justifiable in time and money.

Build a "well" around the afflicted zone, then after both chemical and reverse-electrolytic cleaning, electroform new metals into place, mill it to shape, grind, scrape, or both.

I say "electroform" in the sense that it is an electrolytic plating process, mildly elevated temps, only, but can go to four inches and more in thickness, not but a few microns, nor classical "brush" plating as we know it.

May or may not be a "candidate", but K.C. Jones routinely plates ""Miccrolloy" Bronze to a tenth of an inch, ISTR has done a third of an inch for specials or experiments.

Early Cold War, before the necessity of "ablative" re-entry shields for ICBM missiles was accepted, there had been experiments to electroform high-temp alloys to long, hollow, spike nose "cone" shapes similar to bullets, and at previously unheard of thickness and uniformity.

Cost? I did say "cold war"?

Exotics aside, is there an upper bound, other than cost?

"Infrastructure" to make it work, and in an automated manner? Cost? Time? Which metals it might work with?

Probably don't really want to even ASK?

At some point.. we really DO have to simply consider finding a better USED machine-tool. Or even a NEW one.

More goodness comes in the door with either package than just the one ration of improvement, after all.
 
The 350 chevy I built at 17 had a forged truck crank in it that I pulled out of a farmer's field. The engine builder told me I had to have that crank sand blasted before he'd even look at it and so I did.

For 17, I did an appropriately adequate daily number of 7200 RPM shifts and more than a few stuff the tach needle where it didn't belong bad shifts and that crankshaft didn't give 2 shits even with pits in the rod bearing journals you could lose a BB or two in.

Run the POS.

The pits WERE filled with rust before you cleaned them out. Might have been better off before you took it apart lol!
 
I think you’ll be fine if you just clean all the rust out with some cleaner and a brass brush or bristle brush. They are just like added oil retention pockets.
 
Don’t heat it or weld it I fixed my 4020 table that someone got read drill happy with. Had a fixture plate with a 4th axis on it looked real nice so I get it home and fudge so I spray welded the holes shut and warped the shit out of it, lucky for me I have other machines large enough to machine the machine, cut the top then set up and machined the lower ways flat and true even rapid fed and cut the “teeth”back in for the turcite glue then scraped it all back in and I have a nice mill now after another 5-7 thousand in little stuff
Since it’s a baby if you really want to fix it why not pull the x y carriage and have it hard milled true? Could lap the mill marks out if the surface finish needs to be better. Add new turcite to the bottoms and get a nice straight mill again. Lots of work though if you have the patience


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Zeus: I would clean the pits out and then either leave it alone (and try not to look at it every day lol) or fill it with epoxy. Either way I think I'd call it good at that point, it sounds like you're taking care of all the other more important stuff already!

I share your love for old Fadals. My first one paid for my second one, and I certainly consider the money/time sunk into both very much worth the while!

-A
 
If you have actual pits, and not just areas that are worm=n low, then filling with epoxy is good.

The idea is not to build up a way surface, but rather to fill up the pits with something that is not chips. Pits collect crap, usually chips and dust, which is then rubbed on the bottom of the part that passes over the pits. So filling them with epoxy is a good plan just to avoid anything worse filling them up.

Do about 5 passes with solvent, then one more for luck before filling. Rub down with an old dull file, or a purpose made burr file, and go back to wook.
 
Thank you all for your insights. Im still tossing up what to do about this, while contemplating, all 3 screws have been reballed, thrust bearings re shimmed and repacked , Gibbs(which I made out of bronze in 2003, during its first rebuild) were rescraped, lube lines and metering units replaced, all 3 motors repaired( 2 had loose magnets ), y resolver replaced, new x axis cable assy using liquitite instead of andaconda conduit...turcite still needs to be recut and the way delt with.
I had actually thought about trying to electroplate the way to build it up, just didn't really consider it! I do agree that the pits are crap traps, so while it is tempting to just slap it back together(it was still holding +/- .001, which is crazy all considering)I still need to come up with a way to fill in the pits. My standing issue with epoxy is if it lets go, now I have garbage eating at my fresh cut turcite.
Maybe Ill try a plate of steel with the brazing idea and see how much it moves, this saddle weighs 600 lbs, I'm not sure how much warpage would be induced by heating a dime size area at at time .06 deep, which seems about right. I was talking with a. local guy who grinds/rebuilds crankshafts and he welds cast iron cranks and claims to have very minimal warpage issues.
I need this machine to run reliably for a year, if things pick up, I will replace it. Right now its what I got and Im the one stuck with the machine payment, soooooo
 
I've had epoxy in some gouges in a lathe bed for probably 10 years, and nothing has let go yet. It was not any special type, just an ordinary hardware store clear epoxy, IIRC.

Clean the crap out of the pits to get all the oil out, then clean once or twice more. Should be good all you are doing is just filling, there is no structural function, and really no force that might pull it out. Way oil has not bothered the filled areas.
 
Thank you all for your insights. Im still tossing up what to do about this, while contemplating, all 3 screws have been reballed, thrust bearings re shimmed and repacked , Gibbs(which I made out of bronze in 2003, during its first rebuild) were rescraped, lube lines and metering units replaced, all 3 motors repaired( 2 had loose magnets ), y resolver replaced, new x axis cable assy using liquitite instead of andaconda conduit...turcite still needs to be recut and the way delt with.
I had actually thought about trying to electroplate the way to build it up, just didn't really consider it! I do agree that the pits are crap traps, so while it is tempting to just slap it back together(it was still holding +/- .001, which is crazy all considering)I still need to come up with a way to fill in the pits. My standing issue with epoxy is if it lets go, now I have garbage eating at my fresh cut turcite.
Maybe Ill try a plate of steel with the brazing idea and see how much it moves, this saddle weighs 600 lbs, I'm not sure how much warpage would be induced by heating a dime size area at at time .06 deep, which seems about right. I was talking with a. local guy who grinds/rebuilds crankshafts and he welds cast iron cranks and claims to have very minimal warpage issues.
I need this machine to run reliably for a year, if things pick up, I will replace it. Right now its what I got and Im the one stuck with the machine payment, soooooo

F**ks sake. "a year" you just buys a bag of chip brushes. F**k with it too much longer yer one-year payback just turned into 13 to 15 months off the back of time wasted and money blown on third-party service, then MORE time-wasted to do the trim-up.

Also feel like a pure fool that no-warp weld-up dasn't warp. It cracks, instead.

It ain't always ABOUT "your" work or a lucky guy pushing luck. There are dice to be rolled.

Yah figure every casting ever made was shipped flawless and stress-free?

It IS what you got. Run with what is.

"Wished-for" always costs more even if it ain't on forever back-order.
 
A year of payments is about 25k, feel free to cover them for me....
Fix it right or fix it again....
There is a difference between a weld and a puddle of braze...considering options is always a good idea.
It consistently amazes me that folks who don't actually MAKE the payments are the first to scream replace it. Machinery that sits gets issues, this stuff sat awhile I was working else where, the assignment is done. Consider this a start up again that owns everything, if I have learned one thing about running a shop is hold onto your cash and don't buy anything unless you have a job for it.
It is always about pushing your luck...
 
Lead free plumbing solder is nearly as hard as brass, yet melts at a much lower temperature. Some here have used it for a quick and dirty rehab of lathe half nuts. That might be a middle ground between epoxy and braze/silver solder.
 








 
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