Corrosion of Alde Convectors

BrianZ

Yeah, good points, @Dutch061, but the suggested use is as a gasket sealant for aircraft engines, not hydronic heating systems, plus Loctite has disclaimers in that MSDS that says users must determine whether use in other applications is  effective, and that would be Alde I believe.

The only thing missing from your ground wiring guide is how to run the wires when the battery, junction box & battery switch, etc, are all located outside; however, given the many different T@B configurations, I can understand why you may not have tried to address them all.  This is proving to be my greatest challenge, since the original conduit to the outside in our T@B is already maxed out with wires crammed into that half inch tube.  I'll have to drill a new hole, which takes some careful planning.  The ground wire to the Alde is very simple by comparison.

Dutch061

I should have clarified when I mentioned "aircraft", meaning if there were ANY corrosion issues related to the Loctite sealing compound, it would never be approved for aircraft use.

So, even though it is interesting, I don't believe that the Loctite sealing compound is the cause. If anything, I would suspect it may have been something else that NuCamp may have used during assembly. Even then it is doubtful only because the corrosion isn't on every camper.

I believe that an Alde hydronic system is under much less stress and temperature exposure than anything used in on an internal combustion engine, and there is zero pressure against it. If it was used by NuCamp during assembly of the hoses to the convectors, it was as an added insurance against seeping hoses. Using the steel tension clamps on the hoses, should have taken care of any weeping caused by temperature changes without adding a sealing compound. 

It is perplexing at best is about all I can add at this point. I would like to know the root cause, for everyone's sake!

Brad

BrianZ

@Dutch061
Hey Brad, now that I'm finally getting around to trying to implement your Alde/Airstream-based wiring update guide for installing new ground wires, I'm finding they don't exactly translate to the older/smaller WFCO model that many of us have.

Specifically, for example, compare your WFCO photo on the previous page to our WFCO model WF-8735 shown below..

After removing the front door and two faceplates, I  see there is no cable clamp for attaching 12V main pos/neg wires to the converter. The main ground wire from our bus bar goes directly to a PCB board, so there is no option for adding or changing the wire to larger gauge without further disassembling and desoldering/resoldering the wire to the board.   

On the other hand, it is a short run from converter to the ground bus bar, so may still be worth upgrading the long ground run to the junction box & battery at the front of our trailer.  Also, on our bus bar, the 8G ground wires to the converter and to the battery are reversed (L-R), not that it matters, though it may be better to have them close together or next to each other.

I'm not trying to find fault and still appreciate  the info you've shared, but just wanted you & others to be aware that some parts may not apply to other converter models.  I've already got a new ground wire on the Alde and still plan to run an 8G from ground bus bar to front junction box & battery.

ColoradoJon

After reading this it looks like I will need to do a more thorough inspection and consider changing out the fluid.  In preparation for this I decided to give my Dad a call - he's a retired chemist and has done a lot of water treatment work for cooling and heating systems, working on a wide range of industrial systems like power plant turbines and nuclear power plant cooling systems.

Aside from corrosion caused by dissimilar metals and oxidation, the biggest concern is from biological contamination.  This type of corrosion is very common in closed loop systems because the system itself and the glycol used can *never* be 100% sanitized, and it creates a perfect breeding ground for bacteria.  There is always some amount of bilogical material (bacteria) in the glycol, fittings, and materials and over time this bacteria will consume the glycol, breaking it down into crystals and other minerals and materials.  When this happens the pH of the glycol will change (it usually drops, but some organisms can cause it to increase) and the system can develop biomasses (dead bacteria, material waste, etc.) that tend to accumulate at junctures and fittings. These biomasses attach to surfaces in the system, and those surfaces will eventually corrode.

Biological contamination always exists to some extent.  It can also be introduced to your system inadvertently - topping off your reservoir with old, contaminated, or improperly stored glycol, mixing your glycol with impure water - mixing it in dirty buckets, using tap water or rain water, or by leaving the cap off the filler reservoir, etc.

All you can do is mitigate it with regular maintenance - regular fluid changes and system cleaning.  There is a thread somewhere about changing from Century TF-1 to Rhomar RTU, and Rhomar recommends flushing and cleaning your system before using their product.  They recommend their cleaner, Hydro-Solv 9100 for the job.

You definitely want to use the cleaner before adding new Rhomar glycol, and even between flushes.  The reason is NOT to flush out the old glycol.  Their cleaner removes biological contamination, corrosion residue, crystallization, and other contaminants.  If you don't do this you may be contaminating your new glycol right from the start!

My Dad was super helpful - we looked at the data sheets for the Rhomar products and discussed the differences between Rhomar and Century, and also reviewed the system cleaning process.  He had some recommendations for our small Alde systems, which I could detail in a different thread if there is interest.

Denny16

Perhaps the corrosion occurred where the Loctite compound was not evenly applied, and allowed the glycol to pool in the space not properly sealed?

Cheers 

pthomas745

@ColoradoJon Please send your dad the Forum address, and I bet we can set him up with an honorary membership.

Did you show him any of the pictures of the corrosion we have collected in the last couple of years?

Dutch061

The ground wire between the Converter and the PDC does NOT need to be replaced on NuCamp. It is the ground wire (8-gauge) between the PDC and the batteries that needs to be larger. Please see the attached instructions that I had previously posted, specifically page 6.

Brad

BrianZ

@Dutch061
What are you referring to by "PDC"?  Also, on page 3 of your document, are those photos of Airstream or T@B electronics?  It clearly states replacing the 8G ground going to the bus bar.  I had assumed this was a larger/later T@B converter, because it's not clearly stated.

In my last post, I'm referring to the ground wire between the WFCO Power Center and the nearby ground bus bar.  If you're including the bus bar as part of the PDC, and saying that ground wire between WFCO Power Center & bus bar does not require replacement, then great!  Thanks.

Dutch061

@BrianZ, no offense intended but if you look at page 5, you will see where I call out the "Power Distribution Center (PDC)". My typing skillset is very subpar for someone with my background and experience, so I try to shorten things, when possible, rather than typing it out each time. 

The ground wire between the PDC and the Bus Bar should also be 6-gauge. Basically, the only ground you don't upgrade is the one between the Converter and the PDC, since it is soldered to the Converter and not really an issue. 

In my case, since I removed the OEM Converter from the PDC and replaced it with a Converter under my bed within 16 inches of the battery junction block; installing larger ground wires is not really necessary. Since my voltage drop at 50 Ft of 8-gauge (power and ground) will be less than 5% at 10 Amps and just and just over 7% at 16 Amps, I will be just fine.

If you were to install larger (6-gauge) or add a second 8-gauge wire for both the power and the ground circuits from the PDC to the batteries, you will also fix your inability to properly recharge your batteries. Meaning instead of it taking 24 to 36 hours, you can cut it by at least 2/3rds. This was my main purpose in moving the converter closer to the batteries. I can get a full 60 Amps from my converter through my BMV-712, which means I can be down 360 Ah and be full in 6 hours. I have 400 Ah of Battleborn Lithium. 

Please let me know if you have any additional questions. 

Brad

BrianZ

Thanks, Brad.

Denny16

Brad’s WFCO/PDC is located in front under the dinette seat in his TaB400, so the AWG 8 ground wire was not big enough for the long run from the front to the rear of the TaB where the batteries are.  On the older and newer models, the PWD is in the middle, either under the wardrobe locker or in the galley cabinet.  But upgrading the ground wire from the WDC to the ground buss bar and to the battery is not a bad idea, and can only help reduce or eliminate ant voltage drops and reduce heat in the ground wires.

Nice write up Brad, thanks for sharing.  Upgrading the two ground runs and the ground bus bar is on my list of mods to do to our TaB400.
 Cheers 

Dutch061

@Denny16,

Here is a Link to the WFCO website. 

https://wfcoelectronics.com/

Please provide a resource for your reference to WaCo, as the only thing I can find is Waco, TX. 

Thanks!

Brad

BrianZ

Thanks, @Denny16.
PDC + PWD + WDC = Acronym salad! 

Denny16

Thanks, Brad, my IPad did it agin!  I corrected my post, I meant the WFCo
Cheers 

ColoradoJon

pthomas745 said:

@ColoradoJon Please send your dad the Forum address, and I bet we can set him up with an honorary membership.

Did you show him any of the pictures of the corrosion we have collected in the last couple of years?

He read this thread thoroughly and was shocked by some of the pictures, especially the corrosion in the pics posted by @fstop32

He started to lose track of the issues as the thread appears to be branching out to different topics.

ColoradoJon

Just following up - I did a thorough check of my system and found no corrosion whatsoever.  Convector fittings look new, no bulges, no buildup in the hoses, nothing.

I have never changed out the fluid.

bergger

That's good news.  Especially for a 2017 trailer.  Ours is a 2021, built in Feb of 2020, so not as old as yours but I did an external inspection of all our convectors, I did not remove the tubing, and saw no bulging at all.  I did go ahead and replace the century with Rhomar just to be safe.  Maybe there is some environmental factors or anomalies that are causing it to happen in some trailers and not in others.  

ScottG

@ColoradoJon, how much use would you say your Alde gets, particularly with regard to using the cabin heat?

fstop32

Good to hear @ColoradoJon!

ColoradoJon

@ScottG - That's difficult to measure.  Lately we have averaged around 6 camping trips per year.  These are usually two night stays.  We always run the Alde for hot water and cabin heat at night.  Colorado is usually cool at night, even during the summer, so it runs occasionally in the early morning hours.

Overall I would say the Alde isn't heavily used at all, although I believe that the issue isn't how much use it gets but the condition of the glycol in the system.

After a long discussion with my father about the problem I am convinced that the problem is biological contamination in most cases where corrosion is severe in shorter time frames.

Dutch061

I believe there are many factors to consider, which makes this much more difficult to determine a "Root Cause".

• Usage (how many hours is the Alde on VS active, are you using propane or shore power)
• Glycol PH and Age (condition oof corrosion inhibitor package) 
• Dry Camp VS Shore Power (feedback current in the ground circuit)
• Interaction between the Glycol and the hose sealant at the convectors
• Battery State of Charge when using IE was dry camping for several days and now, I am camping with shore power (with WFCO Convertor installed in the Power Distribution Center)
• Century Glycol VS Rhomar (reportedly a superior protection package in Rhomar)
• Ground integrity (ground missing for Boiler)

Plus, the potential as mentioned by @ColoradoJon for some sort of biological contamination that makes it more aggressive. 

I guess the only thing a person can really do is to take the steps of prevention and monitor it. Based on feedback by a few who have seen corrosion, it appears that the change to Rhomar has prevented it from getting worse.

Brad

BrianZ

Since there has been much discussion in this topic about upgrading ground wires, I thought I would mention that I have shared how I ran an additional 8G ground wire from the converter bus bar in our 320S through a new conduit location in the floor at front to the junction box under the tongue..
https://tab-rv.vanillacommunity.com/discussion/comment/188881/#Comment_188881
This is in @ScottG 's cleverly named topic, "The Secret Life of Wires", which seemed like a more relevant topic, though it may impact this one too, as I've also shown our new ground wire to the Alde. I still have to add the last segment of 8G ground from the J-box to the battery.
I've also abandoned the glycol tank anode rod experiment for now, since I'll be upgrading to Rhomar at the next change, and combined with the new ground wires, this seems more promising than an unproven method, when I've already addressed the convector stubs corrosion issues in our T@B.

MarkAl

Since you mentioned the Alde ground wire @BrianZ. While I see poor grounds on various metal objects in the trailer the Alde box on mine is not one of them. I get approximately 7 milliVolts from the Ground bar to Alde running on Propane of City power. I can only believe my Alde has a better ground setup then others from the factory. I have read much higher values which I agree is disturbing.  

qhumberd

Dutch061 said:

The ground wire between the Converter and the PDC does NOT need to be replaced on NuCamp. It is the ground wire (8-gauge) between the PDC and the batteries that needs to be larger. Please see the attached instructions that I had previously posted, specifically page 6.

Brad

I am also a bit confused due to language in the Airstream bulletin and the differences in the 320 and the various 400 models. So I have the 2 6V AGM Harris batteries in a box under the bed in my 2019 (Oct 2018 build) 400BD. I have flushed the system well last season and replaced the glycol at that time with Century. All visible glycol connections appear normal at this time. We have used the Alde for heat some and hot water each trip for about 15 trips since we acquired in spring 2020. Original owner said they used 6 times total.

I added the 14 ga ground wire this week from the Alde case to the Neg on the battery at the terminal studs. It was only about 12-14 inches of wire. Where is the ground bus bar in my 400? Is it in the closet (I have the smaller frig) under the converter cover? I did not want to take stuff apart unnecessarily. And is that ground needed since my converter is so close to my batteries?

Thanks all

Denny16

Yes, it is under the wardrobe locker, lift up the removable bottom panel, and it is on the side of the trailer behind and slightly above the power converter.  I think you should be fine.  I added a small ground buss bar near the battey (as I didn’t have the little black power distribution box) to connect the various battery grounds to, and will run the Alde ground wire to this buss, as it is easily accessed from under the bed.

Cheers 

qhumberd

Great thanks @Denny16. What is contained in the box enclosure in the closet directly behind the converter?

Denny16

The back and most of the converter unit.  This thing is deep, and could be a shock hazard, which is why it is enclosed.  I liked this little detail nüCamp went to the trouble to add additional protection, since the water pump and connections are in here as well, which helps prevents a short or damage to the converter, in case the plumbing springs a leak.  The box should also have a “Danger high voltage shock hazard” label on it.  :*

Also, I f you look closely to where the water fill and water line to the pump goes through the floor (red box in your photo below), you will see this cutout goes all the through the floor to the top of the water tank.  The top of the tank is about an inch below the bottom of the floor, so dirt and dust from going down dirt roads and rodents can find there way into the compartment and into the Alde compartment.  

Red box and arrow show the hole in the floor for the water lines.  If you look closely, you will see the gap above the water tank, and the hose clamps holding the water lines on the tank.

Our 2018 TaB 400 (same layout) was full of fine sand and powdered dust from its maiden voyage to Burning Man on the California Desert.  Took a while to track down where the dust came from, it was this oversized hole in the floor.  I stuffed the area around the pipes with packing dense foam, and a plastic cap.  You need to have access to this spot, as the clamps to hold,d the water lines on the tank are down here.   permanent seal will not work, you need something removable that will keep dirt, dust and critters out,
 Cheers 

qhumberd

Many thanks! We have not a lot of dusty spots in Tennessee but we sure have the rodents. I'm thinking brass wool and a piece of plastic as you mentioned. Learning more all the time thanks to the forum.

pthomas745

This popped up on the FB page this morning. The owners say the 400's build date is Feb 2020, but they have the "yellow" glycol".  They had Alde issues early on, so it maybe possible whoever looked at the system changed the glycol back to the Century "yellow".  (I'm getting more info on that.)

Opinions on how fast the copper should be changed out?  And, shouldn't this whole system be checked for other pipes with corrosion?

Edit: I messed up the dates here.  A Feb 2020 build would have come equipped with the Century glycol, not the Rhomar.

ChrisFix

@pthomas745
The 2021 model year T@Bs came with Century glycol...