MadModder
Gallery, Projects and General => How do I?? => Topic started by: John Rudd on October 03, 2015, 06:34:53 AM
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The table on the Ajax mill I'm refurbishing has some surface defects......some of these are quite deep....>~ 1mm...
What do we think is the best way to refinish the surface to remove these?
I've thought of clamping the table to that of my big mill (Chester Eagle 30 ) and using a fly cutter.....
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John:
The similar topic (drill press tables with a circle of shame) comes up on another forum. The answers that I recall are usually:
- fill with a compatible weld and grind flat (may risk distortion)
- fill with epoxy metal (JB weld or something similar)
- for very few holes, drill out and plug and grind down
- ignore them and be happy
Hope this is somewhat helpful and I'm not insulting your intelligence :D
John.
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Hi John....( talking to myself? :lol: :loco: )
Yeah I've seen various filling in options, but what I was hoping to achieve as a bonus was to rid the surface of the rust covering that it has accumulated too....Potentially I was hoping to off load the mill to sone poor unsuspecting type sell the machine on in good nick.....
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If you do remove much surface depth, make sure you don't take off so much that tee nuts bottom out on parts and accessories when tightened. Also, of course that the surface you leave is as true to the slides and ways, or truer, than you started with. A cosmetic cure can sometimes become a functional issue for a whole lot of different reasons. A buyer who is aware of cosmetic problems won't be upset with the purchase if it's reasonably accurate for its age. One who buys a freshly machined table that is inaccurate will feel resentment. Not saying don't do it, just think about it.
Rust can be removed by the electrolytic process with washing soda and a battery charger using a plastic dustbin.I've even done it in situ with cloth pads dampened with solution and a plate for an electrode over. It's amazing what that can do to an ugly machine surface. It can look new in sheen, and any divots filled with plugs or epoxy filler so everything looks ship shape and well managed, just not perfect.
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I use electrolytic rust removal quite often but haven't done it with rags on a surface (yet). It is quite wonderful how well it works. Won't fill in pits but will certainly remove surface rust. Usually I follow it or in the middle of the procedure, with extra fine steel wool. I haven't used any of the fancy (read expensive) rust removers and am quite happy with my antique small battery charger and a bit of steel wire and some sort of sacrificial steel. The really nice thing about it is that it won't damage your piece if it's left in "too long".
John.
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Best to clean it up and leave it at that,but I have seen the table put on a plano mill and completely planed the top and the slots come off looking new,also if you had holes in you could redrill them to a common size(flat bottom with a slot drill),tap the hole so it took a cast iron plug,have the plug proud of table so you can put a couple flats on to tighten it in with a spanner(not really neccesary as mole grips would do).When its tightened in hole,stick a small tipped tool in and cut the piece sticking above the table flush,make sure you are cutting in direction so it tightens the bolt in-that would get rid of any holes-but is it neccesary?
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Well,
I've cleaned it up with a wire brush and it doesnt look so bad now..... :scratch:
I may give a once over with some wet n dry paper to polish it and see how it looks after that....
The holes are relatively small, there are a few lengthy gouges in the surface but they are not deep....
Might be best to leave well alone?
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I would leave it alone other than a clean up. Any machining that you do could affect the accuracy.
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I filled mine with super glue and cast iron dust , the small ones just with super glue neat it takes a fair bit of sanding off
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Looks a good repair... :dremel: :dremel:
I might give that a go.
That said,I have some aluminium based filler that I got from Halfords might do the job... :scratch: