[How do I?] Im looking for recipe for ahome brew cutting/drilling/coolant fluid

[trapper]

Hi Guys,

Just ran out of fluid and nearly fainted at the cost from my local supplier unless I buy 25 litres i cant get agood price 5 litres does me fine but thats gone up to £30 with vat!!!

Generally I only machine drill or tap brass copper or aluminium and very rarely silver. I've been thinking of something basedon used cooking oil or maybe used engine oil thinned down. I've used washing up liquid today (just call me suds) on aluminium turned at 850rpm seemed to work fine but uses a lot.

Anyone got a home brew recipe I can use?

 

[7HC]

Hi Guys,

Just ran out of fluid and nearly fainted at the cost from my local supplier unless I buy 25 litres i cant get agood price 5 litres does me fine but thats gone up to £30 with vat!!!

Generally I only machine drill or tap brass copper or aluminium and very rarely silver. I've been thinking of something basedon used cooking oil or maybe used engine oil thinned down. I've used washing up liquid today (just call me suds) on aluminium turned at 850rpm seemed to work fine but uses a lot.

Anyone got a home brew recipe I can use?

I can't vouch for it but I've read that equal parts engine oil (fresh, not used), dish detergent and water is good starting point.
The detergent turns the oil and water into an emulsion. If it foams in use then reduce the amount of detergent, if the table starts showing rust then increase the amount of oil.


M

 

[OldMachinist]

You can blend kerosene, mineral oil and lard oil in different percentages depending on the material. For aluminum I would start off with something like 50% kero, 40% mineral and 10% lard. Decrease the kerosene for harder materials and use a 75% mineral/25% lard for steel. If you can get some sulpher based pipe threading fluid you can subtitute it for some of the mineral oil on alloy steels.

These are all just general guide lines as you'll need to experiment to find what works best for you.

 

[7HC]

You can blend kerosene, mineral oil and lard oil in different percentages depending on the material. For aluminum I would start off with something like 50% kero, 40% mineral and 10% lard. Decrease the kerosene for harder materials and use a 75% mineral/25% lard for steel. If you can get some sulpher based pipe threading fluid you can subtitute it for some of the mineral oil on alloy steels.

These are all just general guide lines as you'll need to experiment to find what works best for you.

I can't comment on its effectiveness but there might be some concern as to its flammability.


M

 

[trapper]

I can't comment on its effectiveness but there might be some concern as to its flammability

Yes i thought that too i think im trying wash liquid (diluted) then mixed with used cooking oil....... I've jst mixed some up but its 19.00 hours here so will leave it overnight and see if it remains mixed then give it ago tomorrow morning

 

[OldMachinist]

There's always a risk of flammability when working with oil but what I listed have been used as cutting oil for more than a century. Common sense should always be used when working with oil whether it be cutting fluids or cooking dinner.

 

[PurpLev]

for aluminum I simply use WD-40.

for steel I use lard - it's solid, and one applied to the steel heats up and melts, and eventually evaporates - so there is no dripping mess to deal with

 

[7HC]

There's always a risk of flammability when working with oil but what I listed have been used as cutting oil for more than a century. Common sense should always be used when working with oil whether it be cutting fluids or cooking dinner.

Agreed, although I was thinking more of the kerosene than the mineral oil or lard.


M

 

[7HC]

I can't comment on its effectiveness but there might be some concern as to its flammability

Yes i thought that too i think im trying wash liquid (diluted) then mixed with used cooking oil....... I've jst mixed some up but its 19.00 hours here so will leave it overnight and see if it remains mixed then give it ago tomorrow morning

Used cooking oil can get very sticky and messy although the detergent may possibly counteract that.


M

 

[OldMachinist]

Any plant base cooking oil will get sticky with time used or not if left to dry on surfaces.

Kerosene is safe when used properly. It's a lot safer than WD-40 as far as flammability. The addition of the 10%lard oil raises the flash point to around 300 degrees F. Adding mineral oil raises it futher.

I remember making some submarine parts many years ago from Inconel and the only cutting fluid the Navy would let us use on them was a kerosene/lard oil blend.