coolant selection

[project5k]

I'm sitting here putting together my next order of this and that for my x3, and i was thinking that i could add my coolant to this set of orders.. but considering that i'm planning to run flood coolant, i was hoping to get some more information.

I did some searches for coolants here, and i'm more confused than i was at the start.. so heres my situation.. i plan to run flood, cut mostely alum, but occasionally some steel, nothing exotic like stainless or titanium...

here is where my knowledge gets fuzzy.. i'm thinking that i want something fairly thin, say around the viscosity of water.. but i really dont know whats better.. i know that my pump setup is gonna have a hard time with reall thick fluids..

i would like something reasonably priced, and i'm thinking that i would like to end up with around 5 gallons of usable fluid... I've read about these water sol fluids that you mix so much with a gallon to make the final product.. what do you guys suggest? what have you used, what did you like, dislike? also wondering about it getting nasty, right now i'm planning to use a fish tank bubbler in the main holding tank, i've read that this really helps keep the fluid from going nasty...

i was also wondering about the mix ratios.. i was looking at the grizzly site, and saw that they have a gallon of thier rustlick model h9240 for $50.. how much can i dilute that stuff? 1:1 with water? 5:1 or what? I guess what i'm really asking is if i were to get a gallon, how much useable coolant would i get out of it?

also, whats the lifespan on something like this? if i use the bubbler, and whatnot, how long should i expect the coolant to last before i should replace it? does it "wear out" like engine oil, typically the oil is still ok, its just dirty with carbon and other contaim... does this stuff loose its "slickness" after a while, or does it just get dirty?

my plan is to have the coolant fall from the cutting area, be collected in a catch pan, and then flow by gravity back to the main tank, where it will go through a coffee filter to clean it up.. is this a good idea? can you see any problems with this plan?

I appreceiate any info you can give me...

[Bubba]

what I have been using is 5GAL DSS-700 BLUE OAKFLO METALWORKING FLUID from MSC and the dilution rate is 5% (1:20).
I use it for Aluminum and Steel and it does a fine job. I have not run a bubbler in my catch tank (5 gal), and about once a year, I just dump it and start over again. Here in the humid south, I have more of a problem with evaporation and have to add water as it does "get a little thick" and because my mill/drill is not in an enclosure, overspray outside of the containment system. I go through a 5 gallon bucket in about 3 years.
Oh, by the way, the 5 gallon pail is about $50! When I started, I used Rustlic, but the price was way to much as far as I am concerned.
As far as a filter, I use some "fiberglass screen" material and it seems to do the job. Any fines that I have pass through the pump and the nozzle without clogging.

[project5k]

thats good information.. so you can get the 5 gal, use what you need, and just keep the fresh in its container till you need more.. and thats way cheaper too... so are you mixing distilled water with it or just tap? i was thinking about using distilled just cause "here in the south"(near san antonio) we have lots of calcium in the water..

as for the fines, i'm concerned cause i am using a magnetic drive pump, and i have already experiected a lockup once cause some filings got into the pump... not hard to fix, just annoying....
when you say figerglass screen, what exactly are you talking about, i had 2 pictures run through my head.. one using window screen, and the other was cutting up a cheap airconditioner filter.. i dont know how i made the leap from screen to filter, just the pictures that came to mind in the instant i read it...

[Bubba]

I use tapwater for the mixture and have not had problems. But my water is definitely different than yours. All I can say is give it a try.
As for the screen, yes it is window screen. This works fine for my pump. The current version is a "pedistal" pump which has been fabricated out of PVC pipe and fittings with an aluminum impeller done on the mill. It started life as a takeout from an ice-maker but got modified over time to the point that I just made the whole thing. Fun project and works like a charm.

[project5k]

I've been dreaming about making my own pump.. using something like an old washing machine motor, or something of that sort, and making my own impeller.. but i gotta get the cnc going before i can do all of that...

[Bubba]

My last one was made from an old "sump pump"! Works OK, but AFTER I built it, I found several sources on the net as to why it didn't preform as I expected!

The pressure is proportional to:
Diameter of the impeller
RPM
If you want high pressure from a small impeller, you have to twist it up quite hi or have a fairly big impeller.
I have developed a spreadsheet to show the specific requirements if your interested.

Yep, you need a cam and cnc to develop specific vane profile as the one I used is a natural log function! But it can be done and is really quite simple to do!

[fpworks]

We use Qualichem's QCUT 246C.

Absolutely beautiful stuff for aluminum. Very mild smell, doesn't sour, leaves a really nice clear oil after the water evaporates that really does an excellent job with rust prevention. I leave coolant all over the table at the end of the day and the machine has a nice coat of oil in the morning...and no rust. We mix it at 3-4%.

We don't ever change coolant. The coolant is "consumed" when we throw away chips, so we just keep adding more to the tanks.

5 gallons costs about $130-ish, but remember, you mix it 3-4%, so it goes a long ways.

Make sure you buy a coolant tester for the appropriate range that you intend to mix. Water evaporates out quickly, so you have to stay on top of it.

On the machine that we do some engraving, we use cheapo air filters on the screens...does a great job of catching those really fine chips. A coffee filter probably cannot flow fast enough to return coolant to your pump.

I believe MSC or Enco have a "flood coolant system" that includes pump, lines, and a tank with baffles, and maybe even a screen. Whatever you go with, make sure you use a centrifugal pump.

Best of luck...
Justin

[project5k]

ok, so let me make sure that i understand, your putting about 5oz of coolant in a gallon of water? wow if thats right, then i'm onlu gonna need about a quart to last me a really long time...

i have wondered about the coffee filter and flowing volume.. its something that i'm gonna just have to try...

as for the tester, are you talking about a refractometer? what does something like that cost? i've never been around one so i wouldnt have the first clue how to use it...

the pumps that i have for now are thoes little cheap clearwater pums from harbor freight, they are centrifugal, but on the down side they are magnetic drive, and yes i am aware of the problems that presents... but its what i've got, so i'm gonna try it till i can save up for a real system...

[InspirationTool]

JP...

Currently I have a enco flood tank setup with Rustlick.

Honestly though, If I had the money, I'd go with a FogBuster.

It should be WAAAAAY less mess.

Bench top machines aren't designed to tolerate the coolant, and you get chips in the darnedest places.

If you have a compressor already, I'd suggest you get the fogbuster.

-Jeff

[fpworks]

ok, so let me make sure that i understand, your putting about 5oz of coolant in a gallon of water? wow if thats right, then i'm onlu gonna need about a quart to last me a really long time...

Yes, that is correct. Be advised, this is not the appropriate mixture for ALL coolants. Unfortunately, I think the smallest quantity to purchase is in 5 gallon buckets...I think it runs us around $130 a pail.

i have wondered about the coffee filter and flowing volume.. its something that i'm gonna just have to try...

If a coffee filter can flow match the flow of your pump, then your pump is too small, IMO.

as for the tester, are you talking about a refractometer? what does something like that cost? i've never been around one so i wouldnt have the first clue how to use it...

Yes, but they are available in different scales. Since we use very low concentration, we use a refractometer that is scaled for 0-10% They come with directions and it is extremely simple.

I think mist type systems like the Fogbuster are great. We use a modified SMC unit on our Mazak for roughing aluminum and 3D surfacing. However, for the best quality finishing and any drilling, flood coolant is superior for aluminum.

Best of luck!

[project5k]

yea, i definately prefer the idea of flood over any kind of mist or anything like that.. i'm not too keen on the idea of airborn particles any more than are absolutely necessary... i know that they make some safer coolants, but not really the direction i want to go...

[InspirationTool]

Hence the name "fog buster". It is designed to create droplets, not mist.

I've never heard about someone who had one that didn't like it.

-Jeff