Fix condensation

Axell · Mar 20, 2023

Hi
The tachometer on my mf35x has got some water on the inside of the glass. The tractor has been outside all this winter. Last winter it was in the barn and there was no water in it. But it has a cabinet, so it hasn't been raining on it.
Is there a trick to remove the water or do I either live with it or buy a new one?

504 · Mar 20, 2023

Leave it in the sun it will dry out

Stephen Newell · Mar 20, 2023

Prop a hair dryer blowing on it. Don't get it hot but very warm.

Steve@Advance · Mar 21, 2023

That's not looking good...

About all you can do is try to keep it dry and hope it will clear up with some direct sun or some gentle
heat.

Probably about time for a new one.

rrlund · Mar 21, 2023

Here's something. Tell me what you guys think. What if there was a shop vac duct taped to it and let it suck a
while? Think it would pull the moisture out? I never tried it, but with heat, there's really no place for the
moisture to evaporate off to. It would have to bleed off through the seal with heat.

DanielW · Mar 21, 2023

We had similar problems with a viewing window on some equipment at work once. Once we got
it dried up as best we could, I was able to get in the back and put a couple of
hygroscopic desiccant packs in there to suck out the last bit of moisture and keep it
bone dry (the kind of little packs you see in the pockets of new clothes, or in pill
bottles. You can buy them online pretty cheap). Once it was in there, I wiped a smear of
clear silicone around the exposed joints and cleaned the excess off the glass - just to
try and prevent more moisture from getting back in. It was kind of a last-ditch effort,
but it seemed to work.

Not sure if something like that would work here. You provably can't really get inside
most tachs to put an absorbent pack inside. Just a thought.

Axell · Mar 21, 2023

Using a hair dryer for 5-10 min did it. But two hours later it was foggy.

DanielW · Mar 21, 2023

The problem with heat is it will clear up when you get past the dew point of what's in
there. The two things that will affect when it gets past the dew point will be the amount
of water in there and temperature. So although you probably got rid of most of the water
with a hair drier, you also increased the temperature past the dew/condensation point of
the water that was left in there. It was perfectly clear at first when it was nice and
toasty, but it was probably still pretty humid inside there. Once it cooled down, the
water vapour condensed again on the cold glass and fogged it up.

The only way to get rid of it completely would be to keep drying until all the moisture
is out (which will be quite some time after it 'appears' clear if using a hair dryer and
heating it up), or find some other way (like the desiccant packs) to get rid of that last
little bit. I like the vacuum idea from rrlund - at least that way you're not heating it
up and risking cracking the glass. The only problem is that you're only going to get it
as good as the the air your sucking/blowing through it. Best to do on a cool, dry day.

showcrop · Mar 22, 2023

One tractor has one gauge that gets water drops in it. Next time the sun is on it they are gone.

Axell · Mar 22, 2023

Thought about the vac while drying, but there would have to be some holes in the shell of the tachometer and it would have to be acceptable without dismantling it. It would be temporary anyway.
Why do some tachometers get easily fogged and some don't. Are they vacuum sealed?

Guess it isn't a big deal as long as I can see the pto mark.

rrlund · Mar 23, 2023

I think it depends on how much they're used. The heat from under the hood should keep them dried out. If moisture
sits on the outside at the bottom of the glass, it's bound to seep in to the cracks in an old rubber seal.

Stephen Newell · Mar 23, 2023

When you do get the water out you might remove the gauge and see where moisture is getting in and use some silicone on it.

Axell · Mar 24, 2023

Could be tempting to do so. Especially if you could buy new seal without buying a new tachometer. But I think the steering wheel might be very hard to take off. And certainly don't wanna break anything there.

stevieb49829 · Mar 24, 2023

If its got a light, remove the bulb, dry it out with the hair dryer, and drop a desiccant pouch in it, then put the bulb back. You might try hot wiring the bulb for a few hours to see what happens to the moisture. steve

Fix condensation

Axell

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504

Well-known Member

Stephen Newell

Well-known Member

Steve@Advance

Well-known Member

rrlund

Well-known Member

DanielW

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Axell

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DanielW

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showcrop

Well-known Member

Axell

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rrlund

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Stephen Newell

Well-known Member

Axell

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stevieb49829

Well-known Member

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