I've recieved my aluminium pieces from a metal supermarket and I'm quite disappointed to the finish on the cuts. The cut sides look like a tile that as been scored and snapped.
Anyway, it looks like I'll have to triim them down and wanted to know the best way to do this as I've never done any metal work before. I've got a cheap router on a very crude diy table, and a table saw. Can I use a normal tct router bit or the standard blade that came with my table saw? Which would I get a better finish with?
Also, can anything be done about the scratches on the pannels?
Max pannel thickness is 6mm and material is aluminium or copper.
Anyway, it looks like I'll have to triim them down and wanted to know the best way to do this as I've never done any metal work before. I've got a cheap router on a very crude diy table, and a table saw. Can I use a normal tct router bit or the standard blade that came with my table saw? Which would I get a better finish with?
Also, can anything be done about the scratches on the pannels?
Max pannel thickness is 6mm and material is aluminium or copper.
I would say get some sandpaper and alot of elbow grease. You can get rid of the scratches, and leave a nice finish starting with 220 grit paper and working up to 600 or so. Get the wet/dry stuff and sand the panels under running water to keep the sandpaper from clogging. It shouldn't take too long to get what you want.
-Matt
-Matt
Don't use table saw or router, if you don't have experience with working on metals, the finish won't be good anyway. Easiest way to finish edges is by using belt sander and 100-120 grid paper. If not available, use a wooden block, sanpaper and your hands. Sometimes additional board helps in guiding your block to achieve straight lines. Using soap as lubricant helps too.
I feel like having a go at using the table saw and I've ordered an "80 tooth 250mm 6 degree negative rake non-ferrous tct cutter" from ebay. But now reading your post Peter, is it so much more difficult that you wouldn't recommend it to the novice?
I've recently invested in a myford lathe, pillar drill press, and scroll saw with full intent of learning to work with metal
I do have a belt sander, but I think there may be more than just sanding work required on this job as some of the pieces haven't even been cut square or perfectly straight. I've never purchased from a raw metal merchant before so I don't know if this typical.
You have a proper blade, so it's a first step. Cutting aluminum is not that much different than wood, so if you feel up to it, go for it. Just use safety glasses (they really neccessary) and make sure your hands are never close to work piece.
Here's how I do it: http://www.diyaudio.com/forums/showthread.php?s=&postid=376414&highlight=#post376414
Here's how I do it: http://www.diyaudio.com/forums/showthread.php?s=&postid=376414&highlight=#post376414
Before anyone tries power tools on metal, I really believe they should learn how the material reacts to hand tools. While the techniques are all similar, I have to say that when aluminum decides to resist, it is a different animal than wood or even steel.
IME, use a good 18 tooth hacksaw for most cutting, then use finer and finer cut files shape it down. Watch the "heat" or you end up with "melted" material on your files. If you have a band saw or scroll saw, even better. I've never tried a table saw on aluminum... the risks of "binding" seem too high. If you use the correct type of good quality blades and files with good bite, it shouldn't take much longer than power tools and there is much less risk of injury.
If the surfaces are scratched, there is probably nothing you can do to restore the original mill finish. But you can always give it a "brushed" look by sanding it in one direction only. Don't go back and forth. The aluminum will self-anodize after a time.
ensen.
IME, use a good 18 tooth hacksaw for most cutting, then use finer and finer cut files shape it down. Watch the "heat" or you end up with "melted" material on your files. If you have a band saw or scroll saw, even better. I've never tried a table saw on aluminum... the risks of "binding" seem too high. If you use the correct type of good quality blades and files with good bite, it shouldn't take much longer than power tools and there is much less risk of injury.
If the surfaces are scratched, there is probably nothing you can do to restore the original mill finish. But you can always give it a "brushed" look by sanding it in one direction only. Don't go back and forth. The aluminum will self-anodize after a time.
ensen.For rough finishing, a ******* mill file is my tool of choice. Where a different shape is needed (say, concave curves) a different shaped file is needed.
From there, I occasionally move to some light work with 120grit emery paper, lots of water. Normally, straight from the file to 220, 400, and 600. 600 gives a really nice satin finish, and can be buffed to a nifty sheen with scotch-brite - again, lots of water. You can go to a standard bobbing compound buff from 600 grit as well. If you want flat, get yourself a sheet of 1/4" or thicker glass and place the wet paper on it (grit side up, of course).
If you have experience working with very hard woods on your TS, you'll find it machines similarly to aluminum with one key difference - heat changes the size of metal. The key is to take your time. Heat is your enemy in a very big way, so taking the cut really slow is good (heat can cause it to bind faster than you know how to say aluminum through your stomach). Aside from shape, heat also makes aluminum gummy. I recommend wearing long pants and shirt. Gloves are quit useful if they fit close enough for you to be able to know what's going on. Full eye protection is a must (I use a full face shield) The metal shavings can do *severe* eye damage if one but gets caught in a corner.
FWIW, you can get results as good with hand tools as with power tools, and it only takes a little more time. I don't like working metal with a power sander at all.
edit: one comment - aluminum will NOT self-anodize. It will certainly patina, which can have a very similar result visually. (all metals do this btw - it actually provides a barrier, so constantly polishing the silver is technically NOT the best way to get it to last, but it sure looks purty).
C
From there, I occasionally move to some light work with 120grit emery paper, lots of water. Normally, straight from the file to 220, 400, and 600. 600 gives a really nice satin finish, and can be buffed to a nifty sheen with scotch-brite - again, lots of water. You can go to a standard bobbing compound buff from 600 grit as well. If you want flat, get yourself a sheet of 1/4" or thicker glass and place the wet paper on it (grit side up, of course).
If you have experience working with very hard woods on your TS, you'll find it machines similarly to aluminum with one key difference - heat changes the size of metal. The key is to take your time. Heat is your enemy in a very big way, so taking the cut really slow is good (heat can cause it to bind faster than you know how to say aluminum through your stomach). Aside from shape, heat also makes aluminum gummy. I recommend wearing long pants and shirt. Gloves are quit useful if they fit close enough for you to be able to know what's going on. Full eye protection is a must (I use a full face shield) The metal shavings can do *severe* eye damage if one but gets caught in a corner.
FWIW, you can get results as good with hand tools as with power tools, and it only takes a little more time. I don't like working metal with a power sander at all.
edit: one comment - aluminum will NOT self-anodize.
It will certainly patina, which can have a very similar result visually. (all metals do this btw - it actually provides a barrier, so constantly polishing the silver is technically NOT the best way to get it to last, but it sure looks purty).C
A little lubricant would certainly help the sawing process. I typically use a little shot of WD-40 directly on the blade before starting a cut. Now there are about a hundred other things you could choose but WD is dirt cheap and sold in every drugstore and supermarket.
When sanding aluminum, always use a little detergent soap in the water (a thimple to a gallon?), and always sand with a block. (Obviously using he black, silicon carbide wet or dry paper.)
As for a brushed finish on aluminum, you can count on it looking good for a couple of weeks. That's it. I have found the best thing is to clean the aluminum thoroughly with soap and water after the sanding followed by alcohol washing. It will look pristine after the alcohol washes. Follow up immediately with a clear lacquer finish. If you preheat the oven to about 150 degrees F (doubles as a spary booth), you can blow on a couple heavy coats in a few minutes and let the finish bake for an hour.
When sanding aluminum, always use a little detergent soap in the water (a thimple to a gallon?), and always sand with a block. (Obviously using he black, silicon carbide wet or dry paper.)
As for a brushed finish on aluminum, you can count on it looking good for a couple of weeks. That's it. I have found the best thing is to clean the aluminum thoroughly with soap and water after the sanding followed by alcohol washing. It will look pristine after the alcohol washes. Follow up immediately with a clear lacquer finish. If you preheat the oven to about 150 degrees F (doubles as a spary booth), you can blow on a couple heavy coats in a few minutes and let the finish bake for an hour.
i dont know if its been mentioned, but its a good idea to wear gloves when working with metal. if it has sharp edges, and you need to hold on, if it starts to wobble or slip, you are going to gush blood. ive done drilling without gloves, and without a clamp, and i slashed my hands up GOOD when it caught.
The table saw will work well but has a lot of kinetic energy, here are a couple of tips from my shop, for your own safety. Forgive me if you already know these .
1. Wear a sheet of aluminum, plywood, thick plastic or something tied around your waist as armour in case the saw throws the work at you. Depending on your saw and your height, it will hit you somewhere between the jewels and sternum.
2. Wear ear protection, metal cutting on the saw can be unbelievably loud. A face shield is better than goggles.
3. Use push sticks [http://www.woodzone.com/tips/push-stick.htm].
4. Be aware of the aspect ratio of your part. Parts that are wider than they are long can bind between the blade and the fence, and should be cut with a 'shooting board' or a mitre gauge.
5. Use fine slow feeds.
6. Keep the blade Low, and stay fearful.
7. Count your fingers and your blessings after each cut !
.1. Wear a sheet of aluminum, plywood, thick plastic or something tied around your waist as armour in case the saw throws the work at you. Depending on your saw and your height, it will hit you somewhere between the jewels and sternum.
2. Wear ear protection, metal cutting on the saw can be unbelievably loud. A face shield is better than goggles.
3. Use push sticks [http://www.woodzone.com/tips/push-stick.htm].
4. Be aware of the aspect ratio of your part. Parts that are wider than they are long can bind between the blade and the fence, and should be cut with a 'shooting board' or a mitre gauge.
5. Use fine slow feeds.
6. Keep the blade Low, and stay fearful.
7. Count your fingers and your blessings after each cut !
Keeping fearful shouldn't be a problem, but is keeping the blade low a safety measure, or to aid cutting? It's just that I read something to contrary somewhere...
Here's a pic of the alu.
Here's a pic of the alu.
An externally hosted image should be here but it was not working when we last tested it.
Both. I don't have time to look it up but I recall two issues, first being the obvious one of more blade exposure causing deeper cuts (amputations!), but the second has to do with kick-back, workpiece lifting, and the recommended number of teeth in the work at all times. Sorry can't do any better today. Cheers!
Vikash said:
Check this post: http://www.diyaudio.com/forums/showthread.php?s=&postid=376459&highlight=#post376459
Don't raise the blade, you don't want the back of the blade travelling up. Also consider the splitter and this article...
http://www.newwoodworker.com/kickback.html
http://www.newwoodworker.com/kickback.html
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