Cast Iron

[Peter.]

I'm depressed now because I just recently scrapped some 2" square wieghts about 3' long from some old windows I tore out of a school building. It did cross my mind that they might be machinable but I figured they must be rubbish quality since I'd never heard of it before.

To add insult, I'm just about to buy some decent sized quality cast iron chunks but it's going to cost me a good bit. Guess I should have at least dragged one of those weights home and tried it out

 

[Tin Falcon]

No worries peter one of the ways we gain experience is by making mistakes. The only way to avoid most mistakes is with experience.
The item you need is often the one that just got disposed of two weeks ago.
Tin

 

[GWRdriver]

Ahhh . . . . Cast Iron. I know this flies in the face of the direction model engineering has been going for some time, and I know it's dusty and makes a mess, but good cast iron is my all-time favorite material. It always has been, it always will be. It does everything it's asked to do (turn, bore, mill, drill, tap, file, polish, etc) so well, and it's wot all the bigguns was made of. I'll accept whatever mess it might make in exchange for the pleasure of working it.

 

[lowietje]

I took a old refer compressor apart and its a good source of high quality cast iron

 

[Noggin]

Try this shameless plug www.nogginend.com

 

[Blogwitch]

Noggin,

I just might have to make an appointment and come across to see you. You are not far away, as I only live just down the road in Crewe.

The main reason I don't like using metal suppliers is the carriage and the time it takes to get here. If you had a pick up service, then that would be something I would definitely consider a bonus. For the same cost in fuel, I could have the stock when I needed it, not after it has been half way around the country. If I posted a letter to my neighbour, it would be shipped out to Knutsford (about 25 miles away) to be sorted, then shipped back to be dropped thru their door, at the moment, anything up to a week.


Bogs

 

[FIXIT]

Hi looking at Nogin's (plug) for brass bar i'm afraid you are a bit dear, Try cronus and its free shipping

Steve

 

[Noggin]

Hey Bogstandard,

We dont have a shop as such but you are more than welcome to give me ring and come over.

Hey Fixit,

But are they as charming and delightful as we are

 

[FIXIT]

No but you do seem to have a good range of matterial,
and I've got you bookmarked


Steve

 

[robwilk]

Hi looking at Nogin's (plug) for brass bar i'm afraid you are a bit dear, Try cronus and its free shipping

Steve

Hey Fixit,

But are they as charming and delightful as we are

Noggin just bookmarked you my self
How about a bit of discount for HMEM members ;D :big:

Thanks for the link i think i might be placing a order soon.

Rob.......

 

[Noggin]

Discount, you want a discount, why would anyone want a discount? O go on then you twisted my arm ;D

My poor mistress will have to miss a shopping trip.

 

[Peter.]

Score!

I just picked up four cast iron sash-weights today, that look like really nice castings with clearly defined lettering. I'll take a pic of them later and stick them through the bandsaw see what wins

 

[Tin Falcon]

I have scored the outer skin of weights with a abrasive disk maybe 1/16 deep then put on the edge of and anvil and give a good wack with a hammer breaks right through.
Tin

 

[Peter.]

Lopped one end off one of my sash weights in the bandsaw. It cut slowly and smoothly and the quality looks just as good as any other piece of cast iron I've cut. I'll turn some in the lathe soon to see how it machines.

 

[jpeter]

Some of you guys sound just like my students. They'd willingly waste my $40 band saw blade to save a dollar on a piece of steel. I had a rule about using the schools cutting tools on scrap steel. But, when I wasn't around they'd, janitors too, use my band saw to cut off rusty fence posts. Upon my return I'd ask why the blade had no teeth only to hear someone reply, "it must have been a cheap blade." I can't for the life of me understand why anyone would risk a carbide tool cutting down cast iron sash weights to save $2.00 on a piece.

I'd suggest going to the metal house, spending a few bucks on quality, certified, material and finishing with a quality project and cutting tools that still work.

 

[Peter.]

My bandsaw blades are only £7 a pop and I'm still on the first from a packet of 5 (and cutting this sash weight doesn't seem to have affected it's cutting capabilities). I don't see anything wrong with scrounging material for my home projects, if anything is unsuitable for machining it gets tossed into the scrap.

 

[Blogwitch]

jpeter,

I have been using sash weights for my cast iron for many years, and haven't blunted a bandsaw blade yet with them. Mainly because I don't use a bandsaw for cutting it up. An angle grinder to just score thru the skin, then persuade it to break with a lump hammer, or just dropping it on the floor has the same effect (concrete, not carpet). Then a quickie 'under the skin' cut to remove the hard outer shell. No broken blades or cutting tools.

to save a dollar on a piece of steel

It is a little more than that. I can obtain from one 35 pence sash weight, a good piece of useable cast iron, normally around 13" long x 1.375" OD, which, if obtained from a metal factor, about 15 pounds. I wouldn't call that saving a dollar, more like using your brain.

The quality does vary, depending where you come from. Here in the UK, we seem to have much better quality castings than from what people have said about US castings.

After removing 3" to 4" off the casting, opposite end from the hanging loop, all the dross and crap has been removed, and except for the loop itself, everything is then useable.

It machines and cuts just like any other close grained cast iron, and has been used for almost all the cylinders, engine blocks, pistons etc for the small engines I have made for many years, and I have never come across any problems. In fact, because they are usually over 100 years old, they have 'weathered', and the grain is exceptionally fine, and can be polished to an almost chrome like finish.

I am not boasting now, but the only time I purchase materials is when a customer requires a certain specification, otherwise I use whatever comes from the junk pile for making these little engines, or even tooling. Once you have gained experience in machining materials, you should be able to cut most materials with no or only normal deterioration of your tooling. If ever I break a bit of tooling, say a carbide tip, it is invariably machinist error, by being too eager to get the job done, taking a 0.250" cut rather than a 0.125" cut.

We are not in the 'full sized' world when we make these tiny miracles, so as long as you make the parts out of 'compatible pairs', then really, there are no reasons to go for exotic materials. Cranks and camshafts, for the amount of use they will get in their lifetime, can just as easily be made from free cutting mild steel, then a bit of case hardening afterwards, but only if needed. Only in a very high speed and/or highly stressed engine would I consider using some of the metals that some people seem to crave for, even when making the most mundane little engines.

It all boils down to experience. You get a sort of 'feeling' that what you are using is just fine for the job you are doing, and that has never let me down for many, many years, even when working for a living.


Bogs

 

[Cedge]

I can vouch for the low quality of sash weights from the US. I just junked about 150 pounds of them due to air pockets, extreme hard spots and generally bad grain. Apparently they were made from cleared slag or the cold dregs from other pours. Carbide would hardly touch some of the hard spots and once it did, *POOF* there was another open void. I finally got my hands on some continuous cast Durabar and never looked back.

Steve

 

[el gringo]

I've been getting my class 40 cast iron from Speedy
metals, nice centrifugally cast for my Cly sleeves and piston rings. my last order (for the Silver Bullet I am building) Was a low grade (grey iron?). I made sleeves out of it but will use the good stuff I have left from previous orders for the rings (read scrap box).
FYI
Ray Monahan

 

[jpeter]

Lathing is ok cuz I can sharpen the bit but milling, which I mostly do, is more risky because the tools are so expensive. Cold rolled steel is the worst. I can't count the times I've ruined a bit on a glob of hard crap in a bar of CRS.