# Aluminum Sticking To Tool



## HBilly1022 (Feb 24, 2016)

Yesterday was the first time I turned aluminum and thought it was awesome to work with until I started to bore a hole. The tool kept jamming with Aluminum and then would just rub on the surface instead of cutting. I tried difference turning speeds and spraying WD40 into the bore but nothing seemed to work. I kept getting a tapered bore because of it. I had to keep pulling the tool and grinding the Aluminum off the tool and eventually gave up. I finished the bore bore by wrapping emery cloth around a drill bit and running that through the bore until I got it close enough for my little project. 

What is the cure for this issue?

Here's a pic of my first ever casting attempt and my first aluminum turning project.


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## Kernbigo (Feb 24, 2016)

i believe i read some where bee's wax


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## T Bredehoft (Feb 24, 2016)

Good looking part. The possible problem with metal sticking on your tool could be a condition of the recently cast aluminum, not clean enough or something. 
I second the use of Bees Wax on the tool. It may be of help. 
Good job on solving the boring problem with your intuition.


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## mikey (Feb 24, 2016)

That condition you're referring to is called a Built Up Edge (BUE), a common issue when working with aluminum. The material actually welds onto the cutter, adversely affecting your tool's edge and geometry and scratching up your finish. The best approach is to increase your cutting speed and maintain a feed that is sufficient to produce coiled chips, not long stringy ones. If using carbide there are some PVD coatings that will reduce this but getting the speed and feed correct is still the key.

Oh, nice job by the way!


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## gwarner (Feb 24, 2016)

I do a little aluminum casting my self. I generally do lost foam. Your project looks very similar to some that I have done.
As far as the aluminum what Mike said is correct. Fast and steady feed with sharp tooling. Additionally the lubricant. I like to spray them down before and often during operations. I also find that if I stop and let the piece cool down some I can usually accomplish what I need done.

However with all that said, I have ran into a great variation in the castings I have worked on and some just are sticky. I have not figured out the solution to it yet but I think it is perhaps the source of my aluminum and the temperature I pour it at. I have had issues at every phase. My biggest issues are usually at the band saw. I have tried various teeth counts and lubricants. Some times it will blow through it like it is butter and others I have to put the blade back on 5 or 6 times as it yanks them off.

Good luck. I had a wood working hobby for many years but after casting a gear for a camper that I could not find a part for I have spent a lot of time and money for machinery so I could cast items.


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## mikey (Feb 24, 2016)

Good point, Gwarner, and I should have put in that coolant is important. WD-40 is fine for boring but the specialized aluminum cutting fluids work better. I use A-9 but there are others. Coolant often changes the chip from stringy to coiled so it ejects from the bore better. Aluminum requires a pretty fast feed to create the chips you want and I suggest feeding as fast as you need to get the chips to coil. Aluminum coils tend to be smaller than steel but they will coil when you get it right. Go fast - I usually bore aluminum near 2000 rpm.


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## HBilly1022 (Feb 24, 2016)

Mikey; the thing I find weir d about this is that when I was turning the outside and taking heavier cuts, everything went well but and when I first started the bore cut, it too went well. However when I started taking lighter cuts to sneak up on the finished ID things went sideways. I started with a small carbide boring bar that I had to grind down to get it into the bore but I noticed the bar was flexing as it went into the bore. Can't get a uniform ID when that is going on so I went to plan B and made a boring bar out of an old engine inlet valve. That was a lot stiffer and I couldn't see any flex, even though I knew it had to be happening when the bore was still tapered. Maybe the smaller DOC had something to do with too. Next time I'll try increasing the feed and watch for chips and I'll see about getting some Bees wax too.

GW; I too have been woodworking for a few years and only recently caught the metal working bug. I now have too many hobbies and not enough time for all of them. I told the wife I'm going to have to retire _again_ so I have more time. In the last few months I've acquired a metal lathe, milling machine, built a forge and started metal casting. I might try the lost foam method next. I cast this part in a metal pail full of sifted wood ashes. I think I added too much water and that the escaping steam caused all the porosity. Maybe the lost foam method will avoid this issue.


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## HBilly1022 (Feb 24, 2016)

mikey said:


> Good point, Gwarner, and I should have put in that coolant is important. WD-40 is fine for boring but the specialized aluminum cutting fluids work better. I use A-9 but there are others. Coolant often changes the chip from stringy to coiled so it ejects from the bore better. Aluminum requires a pretty fast feed to create the chips you want and I suggest feeding as fast as you need to get the chips to coil. Aluminum coils tend to be smaller than steel but they will coil when you get it right. Go fast - I usually bore aluminum near 2000 rpm.



Guess I better get some cutting fluid if I'm going to keep turning aluminum. I was also running lower rpms than you stated but I was using HSS for a cutter (well it was actually an old engine valve). The valve initially cut very well but just like the carbide, it fouled up quickly.


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## Bob Korves (Feb 24, 2016)

A lot of boring bars have geometry problems that do not allow free cutting.  There needs to be enough relief below the cutting edge so the entire bar below the cutting edge clears the bore.  Sometimes just turning the bar to a slightly more negative cutting angle will clear the bar away from the bore.  Better yet, grind it correctly.  Also, make sure your boring bar is cutting on the center of the work, height-wise.


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## gwarner (Feb 24, 2016)

"Maybe the lost foam method will avoid this issue.
Lost foam is not with out its own issues, but when it comes to making one off parts that have no draft I can't think if a better way to do it short of a 3d printer or a CNC.

The gear I started with had internal teeth and no draft at all. I tried sand, plaster etc... with  no success.After reading about lost foam I went down and cut the gear using my craftsman router recreator in some foam. Glued on a sprew. Filled a bucket with sand from the granddaughters sandbox around the part and my first pour came out not perfect but better than any I had been able to do.

Just to let you know what a bug it is. I have 6 sets of those gears now(Just in case). My neighbors used to come over when they heard the roar of the burner to see what was going on. Now they don't even seem to notice.


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## Smithdoor (Feb 24, 2016)

If you really what have AL stick Try casting less that 1/2 hr from mold
FYI give as less a day or better heat treat first then machine.
I have try even pudding lead in the pot try speed ever thing up.

Dave



HBilly1022 said:


> Yesterday was the first time I turned aluminum and thought it was awesome to work with until I started to bore a hole. The tool kept jamming with Aluminum and then would just rub on the surface instead of cutting. I tried difference turning speeds and spraying WD40 into the bore but nothing seemed to work. I kept getting a tapered bore because of it. I had to keep pulling the tool and grinding the Aluminum off the tool and eventually gave up. I finished the bore bore by wrapping emery cloth around a drill bit and running that through the bore until I got it close enough for my little project.
> 
> What is the cure for this issue?
> 
> ...


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## HBilly1022 (Feb 24, 2016)

Bob Korves said:


> A lot of boring bars have geometry problems that do not allow free cutting.  There needs to be enough relief below the cutting edge so the entire bar below the cutting edge clears the bore.  Sometimes just turning the bar to a slightly more negative cutting angle will clear the bar away from the bore.  Better yet, grind it correctly.  Also, make sure your boring bar is cutting on the center of the work, height-wise.



Bob, I checked the tool height with my recently made height gauge (glad I made it) but I think you may be on to something with the clearance below the cutting edge. I thought I had enough but didn't really pay attention to the fact that the bore is a small diameter. I bet the tool was rubbing under the cutting edge. I'm going to check that out later.


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## mikey (Feb 24, 2016)

HBilly1022 said:


> Mikey; the thing I find weir d about this is that when I was turning the outside and taking heavier cuts, everything went well but and when I first started the bore cut, it too went well. However when I started taking lighter cuts to sneak up on the finished ID things went sideways. I started with a small carbide boring bar that I had to grind down to get it into the bore but I noticed the bar was flexing as it went into the bore. Can't get a uniform ID when that is going on so I went to plan B and made a boring bar out of an old engine inlet valve. That was a lot stiffer and I couldn't see any flex, even though I knew it had to be happening when the bore was still tapered. Maybe the smaller DOC had something to do with too. Next time I'll try increasing the feed and watch for chips and I'll see about getting some Bees wax too.



How deep is the bore and how big is your bar? Is the bar carbide or steel? What clearance angle does the insert have or are you talking about a brazed carbide bar?

If you are cutting a taper then the bar is defecting, assuming your lathe is level and so on. If your bar is steel then you can only bore 4 times its diameter before it starts to flex. I ask about the cutter because if you're using a solid bar then how deep a cut you can take varies but if you are using an inserted carbide tool then you cannot take too light a cut or tangential and radial forces increase and your accuracy goes out the window. It sounds like the problem might be the type of bar you're using?


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## Hawkeye (Feb 25, 2016)

I basically scanned the posts. Did you mention what aluminum you used? I started with pure aluminum from heavy wiring. Very gummy. Generally, anything that was commercially cast will be a good casting aluminum - Pistons, transmission housings, etc.

Parafin wax works with aluminum, as does Crisco shortening. The Crisco can be brushed on easily. The down side is that the smoke tends to make you hungry.


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## David VanNorman (Feb 25, 2016)

T Bredehoft , I had a 53 Sport coupe  also many years ago . yours looks good.


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## derf (Feb 25, 2016)

Another thing that will help....hone your cutting tool to a mirror finish. That provides less friction and gives the material less to weld to.


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## HBilly1022 (Feb 25, 2016)

So I go out to the shop and check the last tool I was using and sure enough there was not enough relief under the cutting edge. I'm not sure if that was the only issue but it sure wasn't helping any.

Hawkeye; the aluminum I was using came from and old satellite dish that came off the house when the new one was installed. I knew I was keeping that thing for a reason.


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## master53yoda (Feb 25, 2016)

It sounds like the alloy that you used had insufficient silicon in it.     When i cast i use automotive or marine engine castings.  The alloy is 356 and has 6 to 8% silicon.  the closer the alloy gets to pure aluminum the problem you speak of gets worse.     356 alloy will machine with little problem using WD40 or kerosene.    Extruded aluminium, forged aluminum etc i just take into the recycler and trade it for automotive cast.    I also process aluminum ingots for the hobbiest, and small foundry casters across the US.

Pistons make excellent castings, they have a higher silicon content. 

Art b


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## HBilly1022 (Feb 26, 2016)

Thanks Art, that's some good info.


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## gwarner (Feb 26, 2016)

I don't want to hijack this thread but having dealt with the same issue myself. If Art or someone could answer the question.
 I am wondering it there is a way to impart silicon by adding a flux or other additive. I don't usually add anything.
I have been using cast aluminum rims as my source lately but still find occasions of some stickiness and inconsistency.
I don't currently have a source for car pistons but I will investigate further. 
I have melted lawn mower engine parts but I think those are actually something besides aluminum as they seem to melt way quicker.


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## Wreck™Wreck (Feb 26, 2016)

HBilly1022 said:


> Can't get a uniform ID when that is going on so I went to plan B and made a boring bar out of an old engine inlet valve. That was a lot stiffer and I couldn't see any flex, even though I knew it had to be happening when the bore was still tapered.



The bar itself will not cause taper assuming that the rough bore was not tapered to begin with, if the core had draft it will help to remove that first. A boring bar will flex away form the work when it starts cutting and remain so until it stops, several light roughing cuts may be required to make it a uniform diameter  but the finish will be unimportant as it is roughing.
A cutting fluid of some sort is required either way, when I run small parts on a large open lathe and am to lazy to set up the coolant guards I put flood coolant in an open container and apply with a small brush, this will still fling some soup about but far less then flood.

Using flood on a lathe with a 3 or 4 jaw chuck turns the jaws into coolant flingers, a collet setup does not have any flat square rotating coolant misters (-:


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## TOOLMASTER (Feb 26, 2016)

http://www.tapmagic.com/tmalum.pdf


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## Neel (Feb 27, 2016)

HBilly1022 said:


> Yesterday was the first time I turned aluminum and thought it was awesome to work with until I started to bore a hole. The tool kept jamming with Aluminum and then would just rub on the surface instead of cutting. I tried difference turning speeds and spraying WD40 into the bore but nothing seemed to work. I kept getting a tapered bore because of it. I had to keep pulling the tool and grinding the Aluminum off the tool and eventually gave up. I finished the bore bore by wrapping emery cloth around a drill bit and running that through the bore until I got it close enough for my little project.
> 
> What is the cure for this issue?
> 
> ...


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## Neel (Feb 27, 2016)

HBilly1022 said:


> Yesterday was the first time I turned aluminum and thought it was awesome to work with until I started to bore a hole. The tool kept jamming with Aluminum and then would just rub on the surface instead of cutting. I tried difference turning speeds and spraying WD40 into the bore but nothing seemed to work. I kept getting a tapered bore because of it. I had to keep pulling the tool and grinding the Aluminum off the tool and eventually gave up. I finished the bore bore by wrapping emery cloth around a drill bit and running that through the bore until I got it close enough for my little project.
> 
> What is the cure for this issue?
> 
> ...


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## Neel (Feb 27, 2016)

HBilly1022 said:


> So I go out to the shop and check the last tool I was using and sure enough there was not enough relief under the cutting edge. I'm not sure if that was the only issue but it sure wasn't helping any.
> 
> Hawkeye; the aluminum I was using came from and old satellite dish that came off the house when the new one was installed. I knew I was keeping that thing for a reason.


You can use kerosene as it gives an excellent finish and the aluminium won't weld to the cutting edges.


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## denny98501 (Feb 27, 2016)

[QUOTE="What is the cure for this issue?"

The cure for this problem is to use the right type of aluminum for the job.
Scrap yard aluminum is usually a poor substitute for the correct grade.
You never really know what you are getting..
Download the specifications for castible aluminum and pick a grade for what you need.
Google " A guide for aluminum casting alloys".
I prefer 535 if the casting is to be machined.
It machines very nicely right after casting and needs no heat treating.
Type 319 also machines nicely as cast without heat treating and can be arc welded.
Type 356 also machines excellently but it needs heat treating.
I buy 30 pound ingots from a local foundry for $1.00 t0 $1.85 per pound.
It is worth it.
Scrap aluminum usually pours poorly, has all the flaws that your casting shows, cannot be machined without gumming up the tools and tearing.

Dennis


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## John Hasler (Feb 27, 2016)

denny98501 said:


> Scrap yard aluminum is usually a poor substitute for the correct grade.


Scrap is all that many of us can afford.


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## HBilly1022 (Feb 27, 2016)

denny98501 said:


> I buy 30 pound ingots from a local foundry for $1.00 t0 $1.85 per pound.
> It is worth it.
> Scrap aluminum usually pours poorly, has all the flaws that your casting shows, cannot be machined without gumming up the tools and tearing.
> 
> Dennis



I wish I could get such a good deal here. The local scrap yard charges $2 / lb for scrap aluminum. I hate to think what a supplier would charge.


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## BillVern (Feb 27, 2016)

HBilly1022 said:


> Yesterday was the first time I turned aluminum and thought it was awesome to work with until I started to bore a hole. The tool kept jamming with Aluminum and then would just rub on the surface instead of cutting. I tried difference turning speeds and spraying WD40 into the bore but nothing seemed to work. I kept getting a tapered bore because of it. I had to keep pulling the tool and grinding the Aluminum off the tool and eventually gave up. I finished the bore bore by wrapping emery cloth around a drill bit and running that through the bore until I got it close enough for my little project.
> 
> What is the cure for this issue?
> 
> ...


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## BillVern (Feb 27, 2016)

Hold up Billy. You need cutting wax, a small bar sold by industrial supply companies. Costs about @$2.50 / stick. Prevents AL from adhering to tool. Are you drilling or boring? If drilling check the lands on the side of the drill to see if they are rounded. Also, are the flutes sharpened with a primary and secondary clearance equally measured on both flutes? You can look these terms up by googling "drill geometry". I'll have a blog about drilling on my soon to be up website. If boring, check height of cutting edge to centerline. Aluminum is best lubricated with wax, steel with a cutting oil with sulphur. Water soluble oil for both metals while doing production work. Good luck.


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