City Hookup to Fridge Vent Mod (Vanagon Westfalia)

[sped372]

Warm January weather gave me the itch to tinker on the camper; I've wanted to do this mod for awhile. I didn't add a fan (yet) since I wasn't ambitious enough to pull the fridge to tap into a power source, but I'm curious how much of an improvement I'll get without one. I might experiment with rolling a towel and laying it across the interior vents behind the fridge to force some heat out the new exit... in due time once spring arrives and I pull the camper out of hibernation.



I replaced the elbow (visible in the opening above) with a flared plug from the hardware store (not pictured). Don't want any water escaping behind the kitchen when the pump is on!





No turning back now! Cringed a little modifying "new" parts but we'll never use the city hookup.



Cleaned up nicely with a utility blade and some sand paper.





While doing surgery I noticed that the housing had a couple cracks in it at the bosses for the self tapping screws. I just put these new hookups in a little over a year ago, didn't look that closely at them to see if they were cracked when brand new. Just an observation. Everything was still snug but surprised me for the age of the parts.

[Amskeptic]

Warm January weather gave me the itch to tinker on the camper;
I noticed that the housing had a couple cracks in it at the bosses for the self tapping screws. I just put these new hookups in a little over a year ago,

Ah yes, the reminder that modern parts are engineered with just-not-quite-enough integrity.
Are you going to contact the seller of that housing?
Colin
(your vent looks good)

[sped372]

Yes, I plan to... just to inform since I don't really need a replacement part.

Most likely is that parts, even the "simplest seeming" ones, really do require a tremendous amount of testing and vetting before they can be completely relied upon and trusted. Most OEM stuff has literally been analyzed and tested more ways than most people could possibly fathom before they ever get approved for mass production. I can't completely fault GoWesty for this (given the limited information I have) - these things happen. If the cracks weren't there brand-new it could have been a creep-related failure or any other stackup of environmental conditions that led to the cracks forming later.

Lots of factors go into design (geometry, materials, etc) and consequences might not be fully understood until some time has passed. If it's a known issue they're punting on, that's a different story though. I still commend them for taking on the task of reproducing (and improving) these particular parts. In general the quality is very high; hopefully they last.

[Amskeptic]

Yes, I plan to...
If the cracks weren't there brand-new it could have been a creep-related failure or any other stackup of environmental conditions that led to the cracks forming later.

I remember your professional job description, and I must tell you here that my eyebrow is cocked and I am . . . smirking lightly (think: modern FSP dryer fan, remember that conversation?).

AND I tell people working with aftermarket @*^&! plastic that the most likely cause of a crack such as yours is all of us forgetting that there are forces that occur after we have left the job site. Mechanical stress and thermal stress must be taken into account.

In your case, those big honking coarse self-tapping screws in a slightly too-small bore may have very well overwhelmed the walls at first tapping/tightening. My question to you, knowing your experience with these very sorts of assemblies, is do the self-tapping screws have a taper all the way up the shank? Would that cause a two-fold stress failure from over-tightening? a) the diameter of the screw breaches the wall, and b) due to the tightness of the assembly, can simple heating in the sun cause an expansion that cracks the flanges/walls?

I have a thoroughly explicated procedure with my customers when we install turn signal and taillight lenses.
DO NOT OVERTIGHTEN yes, but also:
a) press the housing with your palm to seat the gasket
b) bring up the screws (in a cross pattern if necessary) to sort-of snug
c) rotate the screws a c-hair counter-clockwise

This for every plastic assembly of every car or appliance I come across.
Thoughts, observations, engineering analyses, welcome.
Colin

[sped372]

I wish I knew if those cracks had been there initially. Because yes, the most obvious answer is that could have been formed by a screw that is "too big" for the bore. The more complex answer is that, also yes, forces exist after you leave the job site. All stressed plastic parts will eventually fail by cracking. You read that right, all of them, every last one. The only variable is the time it takes to fail. Those molecules are shifting because of the stress applied to them, if the materials and geometry aren't right the failure will occur sooner than you want it to. If everything lines up properly that plastic part will still fail but we'll all be gone by then.

BTW I'm still in the profession but at a different, more consumer-focused, company. It's a good blend of engineering and art...

[Amskeptic]

A) All stressed plastic parts will eventually fail by cracking.

B) BTW I'm still in the profession but at a different, more consumer-focused, company.
It's a good blend of engineering and art...

a) So my Lexus is on Death Watch

b) Warms my heart to hear . . .

[sped372]

Sent a message to GoWesty and they already replied that they will forward on to their engineering department (they have a whole department!?). As I typed the message the thought clicked, elevated temperatures worsen the creep phenomenon... and I'm modifying that part to try to let out the heat that's being trapped behind it... so, seems like a logical conclusion. I'll be curious if anything really comes from this feedback but I'm glad they at least acknowledged it already.