Can I sand aluminium

[The Bear]

Why? Well I bought an aluminium router table plate and cut the hole in my table top for it. All fine up to that point. I've now got a second plate with a different hole configuration that I want to use instead. It's from the same company as the original plate but is clearly a slightly newer model as it now has their logo on It is supposed to be the same size as the first but is a hairs breath wider so won't drop in. It might just be the powder coating I need to take off the edges or may be a bit of metal, so can I just sand it and will I likely make a pigs ear of it?

I think doing this if possible will be less hassle than making a new template to enlarge the hole in the table top. I can't send it back by the way it was bought in the states not cost effective and too long ago now.

Cheers

Mark

 

[marcros]

if you are talking a small amount, then it could be sanded. Any more then a file might be better.

Should be easy enough to do. Tape a bit of sandpaper onto something flat, then just go forwards and backwards, as people might when flattening a plane.

 

[MMUK]

I wouldn't use normal sand paper. Use wet & dry instead. 240 grade should do the trick.

 

[Spindle]

Hi

I'd wrap a piece of 240 grit around a sanding block, sand off the surface finish and re-check the fit

Regards Mick

 

[The Bear]

First thought was file but the few I have are quite coarse. I've just tried them on the corner of my aluminium ladder and they give quite a course finish hence the thought of sanding, though yes wet dry I can see will be better

Mark

 

[marcros]

Needless to say do it wet.

When I wrote sandpaper it didn't sound quite right, but my wet and dry is very fine. I didn't know that you could get course grits too.

 

[Richard T]

File to nearly size then sand to finish ?
If you can get it in to a position to draw file it, that will leave a less rough finish and will be more controllable around the curve.

 

[The Bear]

Hi
Pardon the ignorance but what is "draw file"?

The curve isn't going to be a problem as I Ahem. Already cut the hole in the top with slightly wrong radius corners.

Mark

 

[Richard T]

Hi Mark,

Draw filing is using the file 'sideways' - parallel to you, like holding handlebars - and pulling it (drawing it) on the metal.

Cross filing is using the length of the file across the metal. It is usual to cross file, draw file and then finish up with an abrasive, cross filing being the most aggressive.

Aluminium and its alloys are very soft and if you don't have much to remove, draw filing may be all you need and leave lighter file scratches to deal with.

Not having had any experience of routers (except the ones with a Hag's Tooth ) I cannot picture the size of the hole you mean. Is it big enough to get a flap wheel or similar into? Might be all you need if there is not much to take off but would leave a nice finish in taking out file marks too.

 

[marcros]

Richard,

The plate will be approx 12" x 8" or thereabouts I would imagine. The hole in the router table sounds like it is about 12" x 7.9999999" and sites on a rebate.

Mark

 

[The Bear]

Marcros has described it fairly accurately. Thanks for the extra info. Will definitely be easier to adjust the plate not the hole. Will have a go at filing and "sanding" at the weekend.

Mark

 

[nanscombe]

Back in the good old days of school metalwork we sometimes used a piece of emery cloth (sand paper for metal) wrapped around a file for sanding purposes.

 

[johnwc812]

Hi,
A tip for filing aluminium and other soft non-ferous metals is to rub chalk into the file's teeth.
This prevents a build up of the clogging metal filings.
John

 

[The Bear]

Thanks guys, it now fits. I ended up filing it, took quite a while to do, my files are not as coarse as I thought. Happy with the result.

Mark

 

[Tinbasher]

Draw filing = imagine you are using a spokeshave. Wrap something around the file at the non handle end or it'll hurt

If it's a very little to remove could you could use the old plate that fits as a template. Attaché it to the new plate and use a router with a bearing guided edge trimming bit to go around the edge? Aluminium routes quite well.

Edit. I didn't see you've already sorted it :roll:

 

[CHJ]

Not that it is significant in this case, but as a general rule you should never use Emery Paper {carborundum (silicon carbide)} on Aluminium Alloys.
The use of emery paper or crocus cloth on aluminium or magnesium can cause serious corrosion of the metal by imbedded iron
oxide.
Any contact with moisture associated with other metals can induce electrolytic corrosion.

 

[Setch]

Anotherv very general rule for aluminium is that if a tool works on wood it'll work on alu, albeit you need to take conservative cuts. This applies to sandpaper, power saws and even edge tools - I've successfully pared aluminium doors more than I care to admit, though I don't usually use my best chisels!