[Cncest]

I was getting reduced cooling water flow through the spindle. Blowing it out with compressed air gave temporary relief. I wanted a more permanent fix. I tried a product called "Lime Away". Poured it right in the storage tank and let it run for several days. Now the flow is like new again.

 

[CharleyL]

I did this with a TIG welding torch to clean out the water cooling passages and it worked there too, but Lime Away is an acid, so don't leave it in the coolant. Wash it out of the system with fresh water and don't use it again until you really need to do it again. It will dissolve the lime and sediments, but will also etch the metal parts. Prolonged use will destroy your metal parts.

Charley

 

[roxanne562001]

I would think white vinegar would work well too but as Charlie said make sure you rinse the system well with clean water afterwards. You could also mix some baking soda in the rinse water to neutralize the acid and then rinse it with clean water.

 

[gmedwards]

I believe there may be more to it. I have never used water in my spindle. I've only used commercial RV water system antifreeze. No mold or off smells over time, and it does the cooling job. I still had an issue with reduced flow. I blew it out, but could never figure out what caused the partial blockage. I keep my cooling system closed, so it wasn't saw dust or other debris. I also kept a filter on the inlet of my pump. It's my guess that there was some "stuff" left in the spindle from manufacturing process and it finally consolidated and plugged things up.

FWIW, CLR and like products are not recommended for aluminum. I could be mistaken, but I believe the internal body and fluid passages of Chinese spindles are aluminum. CLR will pit aluminum, and in an extreme cause, I suppose it could cause an internal leak. Without knowing the fluid passage metal for sure, I'd stay away from CLR type products and anything else that could corrode aluminum.

 

[Cncest]

The flush was complete after a few days. I then dumped and flushed the system. The cooling water flow is now back to like is was new. I use distilled water with a splash of bleach for cooling.

 

[Straightlines]

The spindles’ guts are all aluminum. Certain acids are appropriate for aluminum and others are not. Lime-Away & CLR are both the same acids. As it turns out, espresso machines have aluminum thermal blocks that must be periodically descaled, so I would try a descaler for those. Also, the pistons/pumps for airless paint sprayers have a special anti-corrosion liquid that is used to long term store them, they are mostly aluminum, so I would give that a try as an additive to your water.

 

[TimPa]

of course, the forums are great resources of information... and everone here cetainly tries to offer the best advice.

but, what does the manufacturer say about this situation? i would think that the risk of damaging the interior of the spindle is too large to leave to speculation.

 

[gmedwards]

Most of the spindles are made in the PRC. Getting a reply from the manufacturer on a question like this is unlikely, and if one got a reply, it may not be all that reliable. CLR recommends that its product not be used on aluminum. That the OP may have gotten away with it one time does not mean it's safe or prudent to use. Personally, I don't see the wisdom of taking the risk, but maybe that's just me.

 

[TimPa]

I agree with you Gary, you are right!

i guess I was thinking along the lines of the CNC manufacturer as well (unless you are a DIY'er or did a self-install). i would think that they would have some ownership toward spindle maintenance, esp water cooled... if not, i guess its buyer beware

 

[Cncest]

The label does state "do not use on aluminum" So I thought, this calls for a test. I poured a solution of CLR/water in an aluminum Sprite can. I also dropped in a piece of aluminum bar stock. I ran the test for 3 days. I found no corrosion, etching or anything else. The ratio I used was 14oz/4gals.

 

[jdowney]

I would guess the warning has to do with the various alloying agents more than the aluminum. 6061 probably won't react, but 7075 might - it's primary alloying is with zinc if I remember correctly. Same goes for "aluminum safe" solutions, if the problem is in attack of the alloy it will vary with the alloy.

I find it curious that machines circulating distilled water suffer from this problem at all. Distilled water should not have dissolved minerals that lead to scale - that is the whole point in using it! Very odd...

In my last day job we ran a chiller system to keep some instrumentation at a stable temperature. It was an open reservoir system running 50-50 distilled water and propylene glycol (the food safe one used for RV's - ethylene glycol is the poisonous one). I never saw flow problems due to scale in 6 years there. We had problems due to poor system design - never let physics students do an engineer's job! - but that was just basic misunderstanding of fluid dynamics and an over constrained set of design goals.

 

[gmedwards]

Distilled water would not cause scale. I've long suspected that reduced flow is caused by small debris in the water jacket left over from the manufacturing process. With use, the debris consolidates and reduces or stops the water flow. I once tried poking around on the outflow side fitting with a piece of thin wire. The wire wouldn't go in very far, and I didn't try to force it. The flow returned to normal. If there had been scale, the wire wouldn't have dislodged it. Consolidated debris, which would probably tend to accumulate at the outflow, should dislodge easily, and in my case, did. I don't have x-ray vision, so I am left to draw inferences from what I can observe.

I'm going to continue heeding product warnings. I have better things to do than trying to prove to myself manufacturers give meaningless warnings, or don't know what they are talking about.
.

 

[ger21]

I've seen a picture somewhere of a spindle with the "jacket" removed. It's really very simple. An aluminum "body" with a single large channel running around the outside. If you are getting clogging, it's probably where the ports are.
I've seen recommendations of blowing compressed air through the ports, from both directions, alternating back and forth. This should remove the particles that are blocking the flow. I don't believe that it's scale building up, as the passages are quite large from the pic I saw.