Cleaning scrap for melting

[Vinny]

I just googled soda wash and every other post is contradictory. One says you can use either washing or baking soda, the next one says don't use baking soda, then the next one says either, then ...

[Pete O]

I think I'm going to have to do a little high-school science experiment, put similarly soiled pieces of scrap into jars of various substances for a week and see which comes out cleanest for least cost and effort. So far the contenders are diesel, simple green, caustic soda, bicarb solution. Each plus or minus electrolysis.

Manual cleaning of parts takes me back to 1979 when I was a first-year apprentice motor mechanic and got to wash all the tradesmen's parts. Needless to say I do not want to go back to 1979.

[dallen]

I use car wheels for a source of material, I cut em up and melt them first time around gets rid of the crud and clear coat, second time as I'm using the supply of ingots any thing still in the melt is gone.

if your trying for pure casting alloy aluminum, your probably going to have to buy it in ingot from a supplier.

Any oil or grease will burn off and add fuel to the fire. really dirty bits and pieces take em to the car wash and give em a hose down, or use a pressure washer if you have one.

Busting castings up in a wood splitter, its a good idea to throw an old carpet over the thing before applying pressure to stop any stray bits from entering the body.

funny how even the fun things in life have a bad side to them.

[Dr Stan]

(10-28-2016, 07:48 PM)Pete O Wrote: I think I'm going to have to do a little high-school science experiment, put similarly soiled pieces of scrap into jars of various substances for a week and see which comes out cleanest for least cost and effort. So far the contenders are diesel, simple green, caustic soda, bicarb solution. Each plus or minus electrolysis.

Simple Green only needs to be sprayed on then pressure washed 5 to 10 minutes later. Did this with a lot of the parts on my Fray mill during the rebuild. Worked great.

[Pete O]

(10-28-2016, 08:50 PM)dallen Wrote: I use car wheels for a source of material, I cut em up and melt them first time around gets rid of the crud and clear coat, second time as I'm using the supply of ingots any thing still in the melt is gone.

if your trying for pure casting alloy aluminum, your probably going to have to buy it in ingot from a supplier.

Any oil or grease will burn off and add fuel to the fire. really dirty bits and pieces take em to the car wash and give em a hose down, or use a pressure washer if you have one.

Busting castings up in a wood splitter, its a good idea to throw an old carpet over the thing before applying pressure to stop any stray bits from entering the body.

funny how even the fun things in life have a bad side to them.

Yeah I was starting to wonder if I was over-thinking it, maybe just chuck em in and scoop the crap off the top of the pot. I have an old auto transmission that is covered in thick, oily filth and I have not been looking forward to cleaning it prior to melting, maybe I'll just not be too fussy.

[Mayhem]

Just stick it in the pot!

[dallen]

some people get the metal scrap that they are going to melt clean enough to eat off of, me I waste way too much time just trying to cut the damn things up to spend anymore time on cleaning the bits and pieces.

really thick build up should fall off to some extent.

[Clifford B.]

(10-29-2016, 01:25 AM)Mayhem Wrote: Just stick it in the pot!

Ditto on that !!
skimming the dross is much easier  (and cheaper )
I scrap melt al a lot for re-casting or for re-sale when the
beer and tool supplies need replenished

[texx]

i just hit dirty scrap with the pressure washer then break it down to some thing that will fit in the furnace , anything that is left on the scrap either burns up floats in the dross or sinks to the bottom .

johno

[the artfull-codger]

(10-27-2016, 08:49 PM)Pete O Wrote: I have some old transmission and transfer case housings that I plan to melt at some stage, I'm wondering if there is something I can leave them soaking in for days / weeks / months that will make them easy to clean just with the pressure washer, I'm thinking much like the old molasses bath for rust removal. I don't want to spend the same amount of time cleaning things up for melting as I would for rebuilding the gearboxes, and I don't need the parts in a hurry.

By the way, I've found that my chinese log splitter is an excellent tool for breaking gearbox housings into crucible-sized chunks. Thing sits unused for months on end, might as well put it to work!

What a good idea using a log splitter, thanks I'll try mine out.