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DIY Dehydrator

avrojockey

Well Known Member
Patron
Well...on the recommendations of others I built one. I really wanted to fork out the cash but no-one makes a closed-loop system anymore. Here's what I did after a couple modifications

Materials:
  • 4" PVC
  • 4" PVC Caps
  • Polyfill aka pillow stuffing
  • Stalnless frying pan splash guard
  • 50-60 gal fish tank pump
  • Various 3/8" plumbing fittings based for my application
  • 3/8" poly tubing
  • 1 gal Silicon beads
  • Fuel filter with 10 Micron rating
  • Rubber stopper

The 4" PVC is stacked with about 3" of polyfill then a cross section of stainless splash screen, about 3/4 gal of beads, another cross section of stainless splash screen, another 3" of polyfil, and the fish tank pump on top.

The polyfill on the bottom acts as a filter for oil vapors coming from crank breather and the inlet line is a couple inches off the bottom to trap any liquid oil. the polyfill also helps support the weight of beads.

The splash screen is hot-glued in the bottom but not on top so beds may be serviced.

Cap on bottom is semi-permanently installed with just silicone caulk on outside to seal. The top cap is taped to seal, but make pump and beads accessible.

Fish tank pump cover was removed and slightly modified to slide down ID of PVC pipe.

Section of 3/8" tubing between PVC cap and fuel filter is filled with beads and lightly plugged on both ends with polyfill. This acts as a visual indicator to let me know the interior beads are nearing saturation.

All of this is on a smart outlet for timing, which works with my hotspot with 200mb free data from Freedom Pop.
 

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BTW...the old style charger on the floor in the background...don't use those. I found out it would output more than 16V because my crowbar OVM was doing its job and popping ALT FIELD breaker because system voltage was over 16V
 
When to change?

Tim,

Self-contained and durable - that's nice.

Since you can't see them change color, how do you know when to change the beads? Did you incorporate a hygrometer?

Bob
 
Tim,

Self-contained and durable - that's nice.

Since you can't see them change color, how do you know when to change the beads? Did you incorporate a hygrometer?

Bob

There's a slug of beads between the dehydrator and fuel filter with polyfill on each end to keep them in there...when they start changing from orange to green I know the mains beads are getting saturated. You never need to change those...once you recharge the main beads it will dry these out and they'll go back to orange.

The main issue I ran into with this unit was making sure everything was sealed enough and still remain removable...If I did it over again I might use threaded clean-out plugs and seal with teflon tape.

Also, tank pump has two 1/4" outputs that are joined to one 3/8 output...I noticed when I used a 1/4" tee to another 1/4" line the pump output was restricted.

Price: ~$65
 

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That should work. I also have an air-mattress pump. When I come back from flying, I blow the moisture out of the engine with the pump through the oil filler. You will see vapor coming out of the breather for up to 30 seconds. Can't say if it works but it seems logical. At least it removes some oil vapor that would get in your dehydrator.
 
Hi Tim - Thanks for sharing. If you have time, could you please share the theory of the dehydrator and what you hope it accomplishes in your a/c? Also the way the smart outlet works.
 
Hi Tim - Thanks for sharing. If you have time, could you please share the theory of the dehydrator and what you hope it accomplishes in your a/c? Also the way the smart outlet works.

Air circulating over dehydrator beads keeps water vapor out of the engine case and from condensing on the anything and causing corrosion...Namely the cam and lifter faces. If you fly every 1-2 weeks then you don't need to do this, but there are times when I'm gone for extended periods and I need to protect things.

Corrosion is the #1 reason why engines don't reach TBO.

There are several smart outlets commercially available now. Best Buy Smart OutletsThey connect to the internet (generally wifi) and allow remote access through an online account or app on your phone. I use TP-Link Kasa brand in my home so I just put one in the hanger.

My hanger doesn't have internet access so I bought a cellular (GSM) WiFi hotspot that was unlocked (not locked on a particular carrier). I had service tied to my mobile phone plan with T-Mobile but the smallest plan I could get was 200MB and it was $10/month. I recently found out that Freedom Pop will give you 200MB FREE every month (500 MB if you have a CDMA hotspot), you just need to pay onetime $10 SIM card charge.

Once everything is all hooked up I can schedule and/or remote control the outlets from my phone. See pic...
 

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