Surface plate and straight edge auction find.

[Freedommachine]

It is not technically related to machine reconditioning, but dang it, I'm excited and nobody I know has an appreciation for these things.

I just picked these up from the local auction for (what I feel) is next to nothing. It sucks they left them outside but I cannot complain too much I guess. What do you guy's think, did I make out ok?

The "tables"... Is 'surface plate' the proper nomenclature for these? I know the smaller of the two has handles so that it can be flipped and set onto an object being scraped for an imprint. I have been looking for one for a few years; never thought it would show up here. Unfortunately there was no biax, I couldn't get that lucky.

 

[hvnlymachining]

Sooooo..., You posted just to brag and show off? A bit petty don't you think??


Also, sweet! Looks like all good buys. Now you just have to put all the spare elbow grease you have into them. A Biax at that price would have created animosity anyway.

Post back when they're looking like new and available for borrowing.

 

[Bakafish]

They seem cheap now, but wait until you factor in all the costs to make them usable again I can't tell you how many times I've found a 'deal', then ended up spending a ton accessorizing it with every optional accessory or making it perfect. Even with a Biax, that's going to be a lot of work. You'll need all the metrology gear to get it trued up again too, but good practice.

Those plates look super heavy. Do you have a surface plate and rigging that can support them? The parallels and straight edge seem like the better buy, but if you have the space and the equipment to manipulate them, the plates may turn out useful. Hope they all clean up nice.

 

[Freedommachine]

Sooooo..., You posted just to brag and show off? A bit petty don't you think??

Noooo... To share something interesting amongst like minded individuals; aquire knowledge about the tools and maybe a little advise on what to do with them next... But if you wanna make me sound like an ass, that's cool too.

Also, sweet! Looks like all good buys. Now you just have to put all the spare elbow grease you have into them.

Thanks! Any particular way you would go about skinning this cat?

And btw, I have no problem sharing. If you need something I've got, you're welcome to it.

They seem cheap now, but wait until you factor in all the costs to make them usable again I can't tell you how many times I've found a 'deal', then ended up spending a ton accessorizing it with every optional accessory or making it perfect.

I am guilty of the the same lol. I've been into something more than once thinking; "I'm an idiot, why didn't I just wait and buy a new one".

Those plates look super heavy. Do you have a surface plate and rigging that can support them? The parallels and straight edge seem like the better buy, but if you have the space and the equipment to manipulate them, the plates may turn out useful. Hope they all clean up nice.

Thanks, I hope they clean up nice as well. I do not have a surface plate large enough to lap or even check them. I have an A frame crane that would work well for manipulating the small plate; the big one, I'm not so sure.

If you notice in the pics there is snow here and there; we haven't had snow in months. This stuff has been outside in the weather since at least March, maybe longer.

None of it will be ready to use anytime soon but all of the straight edges can be scraped easy enough. If the big plate is beyond repair, it would still make an awesome weld table (blasphemy I know) and the small plate, I will find a way to recondition it for sure.

 

[Garwood]

I have a good size 48x60 plate from WWII Boeing. I was told it's considered a "layout table" as mine was just planed, not scraped. I use mine as a "clean" shop table/low grade surface plate.

 

[hvnlymachining]

I don't consider it so much "skinning" if they're in similar shape to some that I have received, it's more like an assault, perhaps even war.

I'd start with a bead blast, or power wire brush unless you can afford one of them fancy schmancy Lazer rust incinerators. But to each his own.

Nice buys in any case, if even used once it'll likely justify the cost.

 

[Freedommachine]

I have a good size 48x60 plate from WWII Boeing. I was told it's considered a "layout table" as mine was just planed, not scraped. I use mine as a "clean" shop table/low grade surface plate.

The plates are sitting on what looks like a standard 40x48 4-way pallet. From that; I'm guessing the big plate is 36"x48"-ish. It does look different than a standard surface plate table. I'm thinking both of these were designed to be held upside down and set against something being scraped to act as a reference.

Were the accurate ones really scraped flat? I couldn't imagine how long it would take to scrape a 48x60 area, although idk how else it would happen, maybe a special lapping machine?

I don't consider it so much "skinning" if they're in similar shape to some that I have received, it's more like an assault, perhaps even war.

I have had success on machine ways by soaking pig mat in evapo-rust and covering it with plastic wrap. I might try that on the plates. If there is a somewhat useable surface under there, I'd hate to damage it.

Nice buys in any case, if even used once it'll likely justify the cost.

My dad gave me an old war finish B&S #2 horizontal with all of the goodies and attachments about 10 years ago. These will be put to good use on that project and many more. I'm 31; I've got decades of acquiring knowledge and working on worn out machine tools still ahead of me yet lol.

 

[Garwood]

My big one has the sockets machined in it for the lifting lugs, though it doesn't look like they were ever installed.

I don't see how you could use it to spot anything if it wasn't scraped. Broadnose planing is nice, but not good enough for spotting anything I wouldn't think.

Big, pretty flat surfaces are handy. Doesn't have to be perfect to be useful.

 

[JST]

....................................

Were the accurate ones really scraped flat? I couldn't imagine how long it would take to scrape a 48x60 area, although idk how else it would happen, maybe a special lapping machine?
............................................................

Yep. scraped flat to 40ppi. More work than can be imagined if done by hand.

Start with a straightedge. You will need a reference surface.

Yes, you can do 3 squarish parts by a repeating process, but you don't even want to know how much effort that is. And it does not work well with straightedges. I did it for a set of 3 small right angle references, that was bad enough (did it as practice and just to see how it worked).

Those may or may not be reasonably flat, and "just rusted". See if there is any evidence of scraping on them now. If so, they may be salvageable without as much work, once you are proficient. If no scraping marks, they may never have been more than planed.

 

[M.B. Naegle]

Nice score! Yes it'll be a lot of work to make it all precise again, but all the better when getting it cheap to start with. IMO, the work is too be expected as to buy the same spread of stuff that's ready to go would be tens of thousands of dollars. To buy "good used" stuff that looks good? Might save some work but who knows how good the prior owner did it so IMO rust isn't an issue in my eyes. How it prints in blue is your calibration certificate, and It does require regular renewal.

So I'm counting two inspection plates, two parallels, a camel-back, and what looks like a matching set of parallels, but the "rail-road rail" shape is interesting. The webbing looks like they were indeed made for inspection work, but perhaps a specific job? You can use the parallels for printing, but their size to weight ratio will give you a hernia making multiple rubs on a machine. They're really made to use as inspection surfaces like using an indicator at a higher level than the plate or for indicating a machine's table or ways flatness, or for big machine set-ups (think vise parallel but bigger). Toys this big aren't a problem if you have the work for them (or at least the heart to enjoy them) and some kind of over-head hoist. A little gantry or jib hoist can do wonders. All my 'big' straight edges I can lift on my own, but I made a light-weight rolling jib hoist with a block-n-tackle to handle them with.

The big plate wouldn't be too bad to resurface. I dream of finding something around 4'x10' (THAT'll be a chore), but even without a bigger surface plate to print them against, you can make that 3x4 flat again. Start with a long straight edge (preferably 48 or close to it) and use it to print the plate in an X pattern and along the 4 sides. Print each surface and map out on paper how it prints and most importantly how it hinges. Use a small surface plate to print the whole surface in sections, but only scrape the high spots that you know are high from your straight edge mapping. Do that a bunch of times and eventually the straight edge will hinge right across the whole surface and you'll only need to focus on getting your bearing count up. IMO, 20ppi is fine for a shop floor surface plate. 40ppi is better if you can get it and in line with an inspection grade granite. Even if you don't intend to use them for inspection or assembly, PLEASE don't drill holes into them. IMO that's a bigger shame than letting them get rusty.

 

[lucky7]

That larger surface plate looks to have deep enough webs to warrant a re-scrape, but would as others have said, be a big job. Would want to see bottom to ensure enough webs and a three point pad arrangement before proceeding with scraping.

You will need at least a one ton lift to break marking die stiction and weight of plate. Probably as surface comes in to more ppi, will also need pulling gear just to spot it. Do you have climate control in area the work will be done? A big enough master plate in known good condition, or knowledge of other methods? A Biax? A strong back?

My vote would be just buy a granite plate and use this cast iron plate for something else...

 

[Freedommachine]

I just back with them, I will reply to everyone later this afternoon. I just wanted to update with some more pictures. Unfortunately the small plate looks like a total loss for anything resembling accuracy. Maybe I can clean the paint off and sell it on ebay as a "retro industrial end table"

Camel back is 27.75" long
All other straight edges are 36"
Small surface plate is 12"x35.5"
Large surface plate is 30"x48" it has studs on either end which I suspect was for mounting in some type of trunnion.

 

[Garwood]

Scrape the straightedges. Have that bigger table Blanchard ground or planed and use it as a nice shop table.

I got some good size T-slot floor plates from a friend of mine recently. They look about like your stuff. Pretty rusty. I was trying to think of a useful shop use for them, but just couldn't until I realized I could set them in the dirt and save a lot of time and money over pouring a concrete walkway to one of my shop doors. If I ever need one, I'll know where they are.

 

[Freedommachine]

Those may or may not be reasonably flat, and "just rusted". See if there is any evidence of scraping on them now. If so, they may be salvageable without as much work, once you are proficient. If no scraping marks, they may never have been more than planed.

The camel back and the two railroad track looking ones were definitely scraped. I'm pretty sure the surface plates were too. I wish I would have had more time to investigate this morning. I will clean up little sections on everything this weekend and see how it looks.

The smaller surface plate was one piece I was particularly interested in when I bought all of it. I'm going to give it a detailed cleaning and hope it's not as bad as it looks.

Becoming proficient in scraping, lapping and most important; inspection of mechanical accuracy is a personal life goal for me. The ability to take an old, worn out angle plate, surface plate or machine tool and transform it to a level of accuracy beyond what it was when new... I feel like you'd be hard pressed to find a better superpower lol.

Nice score! Yes it'll be a lot of work to make it all precise again, but all the better when getting it cheap to start with. IMO, the work is too be expected as to buy the same spread of stuff that's ready to go would be tens of thousands of dollars. To buy "good used" stuff that looks good? Might save some work but who knows how good the prior owner did it so IMO rust isn't an issue in my eyes. How it prints in blue is your calibration certificate, and It does require regular renewal.

So I'm counting two inspection plates, two parallels, a camel-back, and what looks like a matching set of parallels, but the "rail-road rail" shape is interesting. The webbing looks like they were indeed made for inspection work, but perhaps a specific job? You can use the parallels for printing, but their size to weight ratio will give you a hernia making multiple rubs on a machine. They're really made to use as inspection surfaces like using an indicator at a higher level than the plate or for indicating a machine's table or ways flatness, or for big machine set-ups (think vise parallel but bigger). Toys this big aren't a problem if you have the work for them (or at least the heart to enjoy them) and some kind of over-head hoist. A little gantry or jib hoist can do wonders. All my 'big' straight edges I can lift on my own, but I made a light-weight rolling jib hoist with a block-n-tackle to handle them with.

The big plate wouldn't be too bad to resurface. I dream of finding something around 4'x10' (THAT'll be a chore), but even without a bigger surface plate to print them against, you can make that 3x4 flat again. Start with a long straight edge (preferably 48 or close to it) and use it to print the plate in an X pattern and along the 4 sides. Print each surface and map out on paper how it prints and most importantly how it hinges. Use a small surface plate to print the whole surface in sections, but only scrape the high spots that you know are high from your straight edge mapping. Do that a bunch of times and eventually the straight edge will hinge right across the whole surface and you'll only need to focus on getting your bearing count up. IMO, 20ppi is fine for a shop floor surface plate. 40ppi is better if you can get it and in line with an inspection grade granite. Even if you don't intend to use them for inspection or assembly, PLEASE don't drill holes into them. IMO that's a bigger shame than letting them get rusty.

Thank you, that gives me hope. I promise, I will not drill holes in any of them.

The large plate doesn't actually look too bad. It has some heavier surface rust in one corner but most of the surface is only covered in a light orange oxide layer. Running my hand across it feels like 2000 grit sandpaper if that makes sense.

I would have liked to see how this plate was used. It was either mounted in a trunnion or attached to a strongback of some kind. The casting is huge compared to a table this size.

 

[Freedommachine]

You will need at least a one ton lift to break marking die stiction and weight of plate. Probably as surface comes in to more ppi, will also need pulling gear just to spot it. Do you have climate control in area the work will be done? A big enough master plate in known good condition, or knowledge of other methods? A Biax? A strong back?

I have a 1 ton gantry crane with a 20' span and a 3'x4' AA granite plate. Other than that, I have nothing else on your list... Yet.

24 hours ago I didn't have straight edges or cast surface plates either . I am acquiring as opportunity presents the things I need.

Unfortunately, this means I end up with a lot of stuff that I cannot use yet. It also presents a bit of a packrat image. I keep telling the wife; "just wait, it will all come together, you'll see."

 

[M.B. Naegle]

When I rescrapped my 8x16 cast iron plate, it did stick to the surface plate, but wasn't hard to pop loose with a little leverage. Bigger plates printing on even bigger plates I agree you'll need something more to get them apart, but not an issue is you work with smaller printing surfaces.

 

[dgfoster]

Just a random thought on the stiction problem that becomes problematic on spotting large surface plates. And, warning, the idea may be “offensive” to those who love large, sparkling, 40PPI, “perfect” flat surfaces. On such a large plate I might be tempted to drill a 1/16” hole near the center of the plate and attach an air hose fitting on the back of the plate. Application of just a little pressure should break the seal between the iron plate and granite surface plate. I will admit that I‘ve never done this and it might not work if the plate simply just flexed enough to allow air passage but not generally released. I will also admit I’d love to try it just to see how it would work! ;-)

When all was said and done a tenth of a gram of grey-colored epoxy would hide the hole and prevent debris accumulation.

Denis

 

[dcsipo]

Sooooo..., You posted just to brag and show off? A bit petty don't you think??


Also, sweet! Looks like all good buys. Now you just have to put all the spare elbow grease you have into them. A Biax at that price would have created animosity anyway.

Post back when they're looking like new and available for borrowing.

He succeeded. I am green with jealousy . But seriously, what a haul, Free should be smiling ear to ear.

 

[TGTool]

Just a random thought on the stiction problem that becomes problematic on spotting large surface plates. And, warning, the idea may be “offensive” to those who love large, sparkling, 40PPI, “perfect” flat surfaces. On such a large plate I might be tempted to drill a 1/16” hole near the center of the plate and attach an air hose fitting on the back of the plate. Application of just a little pressure should break the seal between the iron plate and granite surface plate. I will admit that I‘ve never done this and it might not work if the plate simply just flexed enough to allow air passage but not generally released. I will also admit I’d love to try it just to see how it would work! ;-)

When all was said and done a tenth of a gram of grey-colored epoxy would hide the hole and prevent debris accumulation.

Denis

That's an interesting idea and it ought to work ' "depending." That is, if you assume that the actual plate-to-plate contact area is about 40%, AND that there is actual passage between one low spot and the next, you should get a force roughly equal to 60% of the workpiece area times the air pressure. That should be plenty. OTOH, if there were a nominal seal nearby the air entry hole you might have only 1 square inch times the air pressure. Just crank up the air pressure?

 

[dgfoster]

That's an interesting idea and it ought to work ' "depending." That is, if you assume that the actual plate-to-plate contact area is about 40%, AND that there is actual passage between one low spot and the next, you should get a force roughly equal to 60% of the workpiece area times the air pressure. That should be plenty. OTOH, if there were a nominal seal nearby the air entry hole you might have only 1 square inch times the air pressure. Just crank up the air pressure?

Yes, I am nearly certain using some air as I described would cause the iron plate to become an air bearing. In view of that possibility, having a hand on the plate when the pressure is applied might be needed to prevent the plate sliding off onto the floor if the granite surface plate is not dead level.

Denis