Alde system corrosion

Jetman

Anyone who owns a 400? Several questions, I have just purchased a 2018 400, low time utilization and in very good condition. I tried to take down several panels up front around the divan to see if there were any Alde /lace hoses with major bulging. Seller did not lik3 the fact about disassembling his camper and he has used the Alde for heat these 4 years off and own.

got tr@iler home and I took apart the couch area and there are several places in this front area that have the beginnings of “the bulge”, not bad but are there.

my questions is how does one get the Alde fluid completely out of  the loop so that I can start to open up the hoses and to inspect the proposed corrosion on the aluminum posts on the convectors and specific to the 400 in this area, the connection joints that have been plugged together with the aluminum connectors, and the CRAP squeeze plugs that NuCamp used since new.

cutting the tubes may release lots of fluid, and what can I use to replace the aluminum connectors in this space that is numerous.?

i have heard that 3/4” brass pipe will work, as it is non corrosive to the base fluid, from a video by Mark someone who has done a complete analysis of this fiasco.

The remediation video is very interesting and very informative; however it is related to a 320, not a 400.

Thanks and Help,

jetmandabbs

pthomas745

Under the trailer will be a drain that has a plug firmly attached.  The hose clamp is removed with a pair of pliers, etc.

There are many threads about draining and replacing the glycol.

The whole Forum community worked for several years on a DIY glycol drain/replace/exchange process.  You can find it here under "DIY Glycol Exchange".  Lots of photos and examples in the .pdf

https://tab-rv.vanillacommunity.com/discussion/7722/alde-manuals-and-resources#latest

Look over "Appendix A"

Jetman

Thanks pthomas, will review and hopefully learn my way around the 400

pthomas745

The 2018 400's were pretty new for NuCamp, so they got lots of owners and attention.  This is a basic search for "2018 400 drains" that has many threads on different subjects of winterizing, etc.  Might be worth scanning through and seeing what others have brought forth.

https://www.google.com/search?q=2018+400+drains+site:tab-rv.vanillacommunity.com&client=firefox-b-1-d&sxsrf=AJOqlzVj_X52BlqoULGCVH8e-zcZzTkZpw:1676397421383&ei=bcvrY7v6FrvzkPIPsLSA-AM&ved=0ahUKEwj75LaGy5X9AhW7OUQIHTAaAD8Q4dUDCBA&uact=5&oq=2018+400+drains+site:tab-rv.vanillacommunity.com&gs_lcp=Cgxnd3Mtd2l6LXNlcnAQA0oECEEYAUoECEYYAFC6CVidQGDZRmgDcAB4AIABRIgB2wqSAQIzM5gBAKABAcABAQ&sclient=gws-wiz-serp#ip=1

rh5555

Regarding the OP question of removing the glycol out of a TAB400, here is how I did it:

I have the 2-way fridge, which means the Alde reservoir is easily accessible in the back of the wardrobe.  I unscrewed the reservoir from the wall and dumped excess fluid into a pail by bending it over, then removed the hoses from the reservoir and attached barb connectors them.  The original feed got a right-angle turn to a hose bibb socket, the return line got a 180 degree turn to some Tygon tubing:

I then connected a compressor to the hose bib connector (via my winterizing blow-out adapter and a valve to restrict the flow) and blew most of the glycol into a bucket.  Use about 10 psi on the compressor.

I then changed out the connectors to 2 hose bibs:

And connected 2 garden hoses.  Next I flushed the system, feeding through one garden hose, and dumping the flush with the other.  I ran this till the flush came out clear.

I then reattached the compressor to the feed line and blew out all the water.  That emptied the system so I could detach all the convectors and clean them up.

On my system all the connectors between hoses are rigid plastic and needed no maintenance.  If yours are aluminum, I'd suggest changing them all out.

MarkAl

Now that the corrosion issue is better understood (under the clamping area of convectors) and a fix of some kind (adding a tight fit material under the tube / clamp area). It would be great if Nucamp did something prior to installing the system as this seems to be the current biggest issue people may have with the design. That and making the drain and refill easier would go a long way to eliminating what I hear as the main complaint against the Alde. I love the system, but I haven't had a maintenance issue with it yet.

rh5555

Interesting that Adle has this product on their website: https://www.alde.us/our-products/sealing-compound/?from-search=Sealant

Yoshi_TAB

Hi,

Just an observation in my 2021 320 since there's been discussion about double clamping, some hardpipe to rubber connections do have two clamps (contant pressure type) while some have just a single clamp.  I observe this  at the convector connections, elbows and and straight coupler connections.  There doesn't seem to be a consistant clamp method (single or double) at any point of connection.  The only thing that is consistant is the placement of the clamp on the rubber at the hardpipe interface, which always is  at the end of the rubber piece.  This would  maximize the "stagant glycol" in regards to  the  theory as a contributing root cause to the corrosion issue.

Horigan

@Jetman
An alternative, and I think simpler, method to drain the older 400s is to:
- Open the drain below the trailer/Alde with the red cap to get a gallon out.
- Expose the reservoir in the closet and you'll see a bit of fluid remaining going to one of the two hoses.  There is a check valve preventing that portion from draining.  Disconnect that hose, drain it in a bucket, then tape it to a shop vac hose and pull the remaining three gallons out with the shop vac.  Have a towel in the closet it area to catch any minor spillage while working with the disconnected hose.

Jetman

Thanks Horigan I will certainly give that a try. May be the simplest way yet.

pthomas745

@jetman Here is the original post @horigan made on his shop vac method.  I'm looking at this closely because of how hard the expansion tank is to reach in my 2017.

https://tab-rv.vanillacommunity.com/discussion/comment/164187/#Comment_164187

rh5555

@Horigan, the method I described may seem a little more complicated, but I was doing the full Rhomar exchange as well. I needed to flush out all the previous fluid to prevent cross contamination.  Took about 10 minutes (about 100 gallons) of tap water to do that (after blowing out the old fluid). The ability to quickly switch between hoses, compressors and Tygon tubing (for collecting old fluid for recycling) made this an obvious choice for me.

Jetman

guys 

what I would like to do is to clear out all of the century glycol that is in my 2018 400 so I can address to issue of the small bulge's in several of my pipes and either scotch brite the aluminum to rid the corrosion or either change the tubing to copper with new clips along the bends and joints. The buldges that are on the convectors are very small and should be able to be cleaned, I hope? After I check all fittings I and going back with the century as I have heard that the Romar fluid does not work with older that 2023 models, again ?

thanks for and and all replies 

jetman

rh5555

My reading of the Century/Rhomar change is this: There has been a crevice corrosion issue in Alde systems since day one. The aluminum used in the convectors should have been anodized, but wasn't. Someone at Alde has determined that the Rhomar fluid resists the crevice corrosion better than the Century fluid and is thus encouraging the changeover. It may help newer TABs more, because the crevice corrosion will be less advanced. It will not fix existing corrosion. The only way to fix existing corrosion is to drain the system, remove the convectors, clean up / replace as needed, then reassemble with additional precautions to avoid crevice corrosion starting up again. Using Rhomar fluid will not hurt, and may help if your anti-corrosion precautions are not 100%.

Just my opinion, no official statements from Alde were used in its formulation.

Horigan

rh5555 said:

@Horigan, the method I described may seem a little more complicated, but I was doing the full Rhomar exchange as well. I needed to flush out all the previous fluid to prevent cross contamination.  Took about 10 minutes (about 100 gallons) of tap water to do that (after blowing out the old fluid). The ability to quickly switch between hoses, compressors and Tygon tubing (for collecting old fluid for recycling) made this an obvious choice for me.

Sounds like great reasoning/approach.  I plan to do my switch to Rhomar this spring, which will involve filling and draining with water twice (first tap, then distilled) to remove all the Century fluid.  Just need to find a reasonably priced source of fluid...

I agree totally with your situation summary above.

BrianZ

My plans too, @Horigan.
(Well, except I'll be using my previously documented 3-way valve.)