I saw a shop using the wrong coolant mix for aluminum and it bugged me

Felix Henderson · 2026-03-19T19:30:08.19397+00:00

I was helping a friend at his shop in Phoenix last month and they were running a 10% coolant mix on all their aluminum jobs. They said it was fine, but I know from my old job that aluminum needs a 5% mix to avoid that white crust buildup. We ran a test on two identical parts, and the 10% mix part had buildup after just 3 hours. Why do so many shops think a stronger mix is better for everything?

felixramirez6mo ago

Wait, they were running 10% in Phoenix? That dry heat makes the problem even worse. It's like they're asking for that white powder on everything.

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benc536mo ago

Our shop in Tucson runs 12% on all our aluminum and we've never had that white powder issue. Maybe it's your water hardness, not the mix.

3

the_xena6mo ago

My buddy's shop did the same thing and wrecked a whole batch of fittings. They learned the hard way that more isn't always better.

0