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Removing Black Spots on Trailer


Bill Reed

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My recently acquired second-hand trailer came to us covered in small black spots about the size of a pin head.  I thought they must be bug spots but an internet search says they are mold spores.  I haven't found any way to remove them except for extensive scrubbing with a non-abrasive pad, which would be way too much work for the whole trailer.  Has anyone else had this problem, and how have you dealt with it?  I'm thinking of using a power buffer/polisher but am worried that I might damage the gel coat.  I'd be glad for any advice about how to care for the exterior of our new trailer.

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Hard to say about the spots.  Here in Western North Carolina we have a small bug that leaves the kind of spots you are talking about.  When you rub your finger across them you can feel a slight raised surface.  When you get a "fresh" deposit and remove it there will be an orange colored spot left.  With these "fresh" spots I simply use any automotive detailer or liquid wax to get them off.

With these spots that have "aged" a bit they are a real - bugger - to get off, even when the camper has a fairly recent good coat of wax on it.  I simply use my finger nail and then a polish and then a wax.

Good luck!

Bill

Unfortunately, when left on for more than a day or two these 

2023 Ford F150 Lariat 3.5EB FX4 Max Towing, Max Payload, 2016 Oliver Elite II - Hull #117 "Twist"

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Personally, I would just hire a traveling pro BOAT detailer and say Fix this please! If the gelcoat has aged through neglect and the mold is down inside it, you won’t get it off easily by yourself. You can screw around forever and never get it close to right. Seriously, buffing damaged gelcoat is WAY different than doing your car, it requires different power tools, compounds and a certain amount of experience. Watch some Youtube videos if you want to educate yourself. Take before and after pics and post the results please.

Once the gelcoat is once again clean, slick, and waxed, buy a can of this to have handy, it is what body shops use to prep paint. It is crazy expensive online, I bought four cans a few years ago for $14 each from a local auto body paint store.

770FC1AE-16B5-4510-A03C-C06B5F9EDA0B.thumb.jpeg.f81867d13bf12620925850cb81a6865b.jpeg

 

And also order this synthetic clay bar, for use after washing and before waxing. … https://www.griotsgarage.com/brilliant-finish-synthetic-clay/

Both these items are fine for your cars too. The 3M stuff will definitely remove regualar wax.

John Davies

Spokane WA

 

 

SOLD 07/23 "Mouse":  2017 Legacy Elite II Two Beds, Hull Number 218, See my HOW TO threads: https://olivertraveltrailers.com/topic/john-e-davies-how-to-threads-and-tech-articles-links/

Tow Vehicle: 2013 Land Cruiser 200, 32” LT tires, airbags, Safari snorkel, Maggiolina Grand Tour 360 Carbon RTT.

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I'd start with stuff you have in the house, mildest. It depends on what the stains really are, but it could indeed be mildew. Fiberglass gelcoat has "pores" that can collect tiny amounts of organic matter, allowing mold to grow, without really good wax. Even then, it can happen.

None of these will hurt your gelcoat. Best done on a cooler day, in the shade. Try a paper towel soaked in vinegar, and plaster it to the hull. Let it sit ten minutes. Rinse it and see.

If that doesn't make a difference,  try  soaking a paper towel in hydrogen peroxide, same procedure, different  spot. ( you never want to mix peroxide and vinegar.)

There are many marine mildew removers on the market. Someone, I think @dewdev,  used Starbrite. I recently tried marine 31 on a few stubborn  spots in my bath, with good success, after none of my home remedies worked. All these need to be well washed and rinsed after application. I'd stick with marine products, though, 

A cleaner wax has a mild polish in it, last resort. Best applied by hand. Any polish or compound  is a form of very fine grit, and removes a tiny bit of gel coat.

The wrong tools in inexperienced hands will do more harm than good, as John e Davies mentioned. You don't want permanent swirl marks in your beautiful sides.

Once you get the trailer clean, wax it well, with a good quality wax, and keep it up. Wax seals those pores. 

We wax twice each year, exterior. Now we use collinite, since 3m ultra has been (sadly) discontinued. Interior gets waxed once a year. Last year, I skipped it, and got some spots in the kitchen..

What part of the country did your trailer come from?

 

 

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2008 Ram 1500 4 × 4

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I agree with SeaDawg. Use mildest to start with.

When I purchased my used 3 year old Ollie, there were a lot of black water stains on the side walls that came from dirt (I think) from the roof.

This Meguiar's 67 is what I used to remove black water stains on my Ollie. It is pretty mild as far as compounds go. Some other products also worked but required a lot of rubbing. This Meguiars 67 One Step Compound took off the spots with very little rubbing. I used a cloth to apply it and another cloth to remove and polish it. DO NOT use a power buffer with any fiberglass compound products.

Meguiar's M6732 Marine/RV One Step Compound, 32 oz

 

After I cleaned the the fiberglass I used the below Meguiars Professional Marine wax. I use two coats each spring and another coat in the fall. 

Meguiar's M6332 Flagship Premium Marine Wax - 32 Oz.

 

I have owned four older fiberglass boats over the years. I always used to use Star Brite products or West Marine products but I really love the Meguiar's products better.

Good luck and let us know how you make out.

 

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2018 Oliver Elite II, Twin Bed, Hull #354 

2024 RAM 1500, 4 x 4; Gas. 5.7L V8 Hemi MDS VVT Torque; 3.21 rear axle ratio

Maine 

 

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2 hours ago, dewdev said:

DO NOT use a power buffer with any fiberglass compound products.

Why do you say this? I've followed the advice given in Practical Sailor magazine to restore a chalky and dirty white fiberglass van top which included using a buffer - for amateurs like me they seemed to lean toward a dual action buffer like this one from Shurhold. They wrote that the more agressive rotary buffers like this one from DeWalt present a higher risk of amateurs burning the surface or leaving swirl marks though in the right hands they'll get the job done faster than what I bought and used.

In any case, compound and buffing may not be the best plan of attack, at least not until more gentle cleaning type approaches such as outlined by SeaDawg are tried here, escalating from most gentle through stronger cleaners as needed. 

This is one of several good articles on the topic of maintaining fiberglass in Practical Sailor - it's a great resource which I learned of here from SeaDawg

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Jim and  Yanna, Woodinville WA

2004 Ford E250 camper conversion

Oliver Elite II hull #709

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As I've said many times, the wrong tools in the hands of inexperienced people can cause more problems than they solve. 

We have 40+ years in maintaining fiberglass boats and trailers. I always look to practical sailor for guidance and new tested and vetted products. I'm sure you are very careful in reading directions,  and proper use, as we are. Not everyone is, which is why, I suspect, @dewdev issued his warning. 

The article you referenced was for heavily oxidized (read neglected) hulls.

Compounds and a power buffer are a strong combo. It needs to be done properly,  carefully,  and only when necessary, as you said, @Jim_Oker

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2008 Ram 1500 4 × 4

2008 Oliver Elite, Hull #12

Florida and Western North Carolina, or wherever the truck goes....

400 watts solar. DC compressor fridge. No inverter. 2 x 105 ah agm batteries .  Life is good.


        
 

 

 

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BILL REED I AM NOT THAT FAR FROM YOU (GREENEVILLE TN "THE SOUTH"), BEFORE YOU DO ANYTHING THAT THESE KNOWLEDGABLE WELL MEANING FOLKS RECOMMEND,  YOU NEED TO LOOK AT THIS AND DO MORE SPECIFIC SEARCHING IF YOU HAVE NOT DONE SO.  Having been faced with these tiny black spots first over 40 years ago and 20 years later around a log home, office building, and new home that I mulched around heavily,  I suspect instead of mold spores, that these are from Artillary Fungus, but yes are spores.  A common culprit is from wood mulch.  The fungi shoot their sports toward "shiny" objects like light colored cars, white guttering and siding when the sun shines on them.  It is brown or black and tarlike. Look up this fungus and see ways to remove, but my experience was that it usually leaves a lighter, less noticable, but still a spot remains underneath when you dissolve the tar spot.  Lots of this info on a search. This doesn't help your specific problem, but in my case, it all stopped when I switched from wood to leaf mulch.  I did find some simple, but not easy ways to remove the tar spots, but the longer they're on, the more permanent the spot damage underneath. I found no other way than to work in small segments.   You can improve the appearance overall that's acceptable from a "normal" distance. If you find, a more recent, widespread easier and more effective cure, I would love to hear it, as my research is dated.

Pardon if you've already discovered this.

Ron

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Bill, I think I may know what you're talking about. I recently detailed an Oliver that had little tiny black spots all around the outside. Most of the spots were on the front, next to the wheels, and on the roof. I do believe this is Tar. I tried several different things to get them off such as buffing, clay barring, and even scrubbing. The best solution for was to use a degreaser and a plastic razor blade. with three guys this too us about 2 hours to get all the black spots off the trailer.

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On 4/11/2022 at 9:29 AM, Bill Reed said:

My recently acquired second-hand trailer came to us covered in small black spots about the size of a pin head.  I thought they must be bug spots but an internet search says they are mold spores.  I haven't found any way to remove them except for extensive scrubbing with a non-abrasive pad, which would be way too much work for the whole trailer.  Has anyone else had this problem, and how have you dealt with it?  I'm thinking of using a power buffer/polisher but am worried that I might damage the gel coat.  I'd be glad for any advice about how to care for the exterior of our new trailer.

Bill, I think I may know what you're talking about. I recently detailed an Oliver that had little tiny black spots all around the outside. Most of the spots were on the front, next to the wheels, and on the roof. I do believe this is Tar. I tried several different things to get them off such as buffing, clay barring, and even scrubbing. The best solution for was to use a degreaser and a plastic razor blade. with three guys this too us about 2 hours to get all the black spots off the trailer.

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On 4/11/2022 at 1:25 PM, SeaDawg said:

I'd start with stuff you have in the house, mildest. It depends on what the stains really are, but it could indeed be mildew. Fiberglass gelcoat has "pores" that can collect tiny amounts of organic matter, allowing mold to grow, without really good wax. Even then, it can happen.

None of these will hurt your gelcoat. Best done on a cooler day, in the shade. Try a paper towel soaked in vinegar, and plaster it to the hull. Let it sit ten minutes. Rinse it and see.

If that doesn't make a difference,  try  soaking a paper towel in hydrogen peroxide, same procedure, different  spot. ( you never want to mix peroxide and vinegar.)

There are many marine mildew removers on the market. Someone, I think @dewdev,  used Starbrite. I recently tried marine 31 on a few stubborn  spots in my bath, with good success, after none of my home remedies worked. All these need to be well washed and rinsed after application. I'd stick with marine products, though, 

A cleaner wax has a mild polish in it, last resort. Best applied by hand. Any polish or compound  is a form of very fine grit, and removes a tiny bit of gel coat.

The wrong tools in inexperienced hands will do more harm than good, as John e Davies mentioned. You don't want permanent swirl marks in your beautiful sides.

Once you get the trailer clean, wax it well, with a good quality wax, and keep it up. Wax seals those pores. 

We wax twice each year, exterior. Now we use collinite, since 3m ultra has been (sadly) discontinued. Interior gets waxed once a year. Last year, I skipped it, and got some spots in the kitchen..

What part of the country did your trailer come from?

 

 

 

23 hours ago, dewdev said:

I agree with SeaDawg. Use mildest to start with.

When I purchased my used 3 year old Ollie, there were a lot of black water stains on the side walls that came from dirt (I think) from the roof.

This Meguiar's 67 is what I used to remove black water stains on my Ollie. It is pretty mild as far as compounds go. Some other products also worked but required a lot of rubbing. This Meguiars 67 One Step Compound took off the spots with very little rubbing. I used a cloth to apply it and another cloth to remove and polish it. DO NOT use a power buffer with any fiberglass compound products.

Meguiar's M6732 Marine/RV One Step Compound, 32 oz

 

After I cleaned the the fiberglass I used the below Meguiars Professional Marine wax. I use two coats each spring and another coat in the fall. 

Meguiar's M6332 Flagship Premium Marine Wax - 32 Oz.

 

I have owned four older fiberglass boats over the years. I always used to use Star Brite products or West Marine products but I really love the Meguiar's products better.

Good luck and let us know how you make out.

 

Agree with SeaDawg and dewdev,

We have tried many products on Ollie and after talking to Meguiar's, they recommended using #67 one step compound & Flagship wax for water spots I could not remove with normal washing and waxing. This process also removed black streaks/spots and they will wipe off easily after application of Miguiar's Flagship wax with a wet microfiber towel right after the rain.

For maintenance between wax only I'm going to try Meguiar's #59 Quick Wax occasionally after Ollie's bath to help maintain the  Meguiar's Flagship Wax. Normally washing before waxing is all that is needed without using a compound.

IMG_5726-L.jpg

IMG_6756-XL.jpg

Bill #75 LE2

 

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18 hours ago, SeaDawg said:

Compounds and a power buffer are a strong combo. It needs to be done properly,  carefully,  and only when necessary

Yes, for sure. Compounding, even with super fine "finishing" grit, takes some material off the surface. By design. Not a good way to solve the issue of stuff like mildew that might be creeping down into the micro pores in the gelcoat if you can get them off with some sort of cleaner. And as your first reply to this thread implied, even harsh cleaners will take some toll on the gelcoat so best to work up to that. All this said, having done the relatively small job of rehabbing a neglected fiberglass van top, there's no way I would take on any significant compounding task w/o the benefit of a power buffer (which btw does a GREAT job of buffing paste wax such as the Collinite Fleetwax 😄 ). 

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Jim and  Yanna, Woodinville WA

2004 Ford E250 camper conversion

Oliver Elite II hull #709

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18 hours ago, Ron and Phyllis said:

BILL REED I AM NOT THAT FAR FROM YOU (GREENEVILLE TN "THE SOUTH"), BEFORE YOU DO ANYTHING THAT THESE KNOWLEDGABLE WELL MEANING FOLKS RECOMMEND,  YOU NEED TO LOOK AT THIS AND DO MORE SPECIFIC SEARCHING IF YOU HAVE NOT DONE SO.  Having been faced with these tiny black spots first over 40 years ago and 20 years later around a log home, office building, and new home that I mulched around heavily,  I suspect instead of mold spores, that these are from Artillary Fungus, but yes are spores.  A common culprit is from wood mulch.  The fungi shoot their sports toward "shiny" objects like light colored cars, white guttering and siding when the sun shines on them.  It is brown or black and tarlike. Look up this fungus and see ways to remove, but my experience was that it usually leaves a lighter, less noticable, but still a spot remains underneath when you dissolve the tar spot.  Lots of this info on a search. This doesn't help your specific problem, but in my case, it all stopped when I switched from wood to leaf mulch.  I did find some simple, but not easy ways to remove the tar spots, but the longer they're on, the more permanent the spot damage underneath. I found no other way than to work in small segments.   You can improve the appearance overall that's acceptable from a "normal" distance. If you find, a more recent, widespread easier and more effective cure, I would love to hear it, as my research is dated.

Pardon if you've already discovered this.

Ron

I think this is exactly the problem that I am facing.  But one side of my trailer is covered with literally thousands of these little black spots, so working on each one individually would take way too much time.  This is a two-year-old trailer, but I have only had it a few weeks.  So I don't really know how long the spots have been on it, but I am thinking at least a year.  Most of them are no longer soft and easily removed with a fingernail.  They are hard and tightly adhered.  They are not tar, because I have tried a variety of solvents and nothing removes or even softens them.  Degreasers, soaps, and other cleaning agents don't touch them either.  So far the only thing that removes them is a lot of rubbing with Meguiar's 91 compound, which is way too much work if done by hand.  I'm thinking I have no choice but to resort to a power buffer, but I'm still worried that I will damage the finish on the trailer.  I will say that rubbing with the 91 compound by hand leaves a nice, shiny finish and doesn't seem to damage the surface at all, so perhaps my fears are unfounded.

I'm grateful for all the advice.  As a new Oliver owner it is wonderful to find so much help available on this forum.

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If these are artillery spores, which I'd frankly never heard of til your thread, you're in for a lot of work. And, I'm sorry.

I've looked at literally a dozen websites,  and all of them note that they're really tough to remove, especially if they've been allowed to remain a long time.

A few more home remedies to soften or remove the casings mentioned are cheap mouthwash (especially mint), murphys oil soap, Mr clean sponges, cooking oil, or dollar store awesome cleaner. (I think awesome is a bit aggressive,  especially if not reduced.) 

Some people found success with borax, or tsp, solution in hot water,  which may actually kill the tiny  spores left behind in the pores. (Caustic solutions. ) general conclusion is bleach solutions only remove stain, and don't kill the spores.

I'd try any (maybe all) of the methods first, before I buffed out the whole trailer.

Screenshot_20220412-150902_Chrome.jpg

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2008 Ram 1500 4 × 4

2008 Oliver Elite, Hull #12

Florida and Western North Carolina, or wherever the truck goes....

400 watts solar. DC compressor fridge. No inverter. 2 x 105 ah agm batteries .  Life is good.


        
 

 

 

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2008 Ram 1500 4 × 4

2008 Oliver Elite, Hull #12

Florida and Western North Carolina, or wherever the truck goes....

400 watts solar. DC compressor fridge. No inverter. 2 x 105 ah agm batteries .  Life is good.


        
 

 

 

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Thanks Bill and Seadawg for getting a name that I can now publicly call these things.  The language that I've historically used is not really suitable for mixed company!😇

Given the distance that my Oliver is parked away from the mulch beds I can attest to the fact that these little buggers are packing some pretty powerful ammo!

Bill

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What I've read, so far, is they can "shoot" the spores and clinging tar up to 20 ft or more.

Yikes. 

Hence, the artillery name. 

Good to note,, for everyone.  Our trailer is parked on turf blocks and shell. Any mulch in our yard is cypress, and some distance from the trailer.  

This is super sad. 

Several posters in articles I read  said to work away from home or away from mulch beds. This looks like a major pita. Not common here in sw Florida,  probably because heat and sun kills the fungus that generates the spore pellets. 

Like I said, I have no prior knowledge or experience with this issue.  Common mildew is easy , relatively,  to remove. This crap can live on in the pores,,from what I've read, and bloom again. One guy said it lives on even old wax. Yikes.

2008 Ram 1500 4 × 4

2008 Oliver Elite, Hull #12

Florida and Western North Carolina, or wherever the truck goes....

400 watts solar. DC compressor fridge. No inverter. 2 x 105 ah agm batteries .  Life is good.


        
 

 

 

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8 hours ago, rideandfly said:

 

Agree with SeaDawg and dewdev,

We have tried many products on Ollie and after talking to Meguiar's, they recommended using #67 one step compound & Flagship wax for water spots I could not remove with normal washing and waxing. This process also removed black streaks/spots and they will wipe off easily after application of Miguiar's Flagship wax with a wet microfiber towel right after the rain.

For maintenance between wax only I'm going to try Meguiar's #59 Quick Wax occasionally after Ollie's bath to help maintain the  Meguiar's Flagship Wax. Normally washing before waxing is all that is needed without using a compound.

IMG_5726-L.jpg

IMG_6756-XL.jpg

rideandfly: I would  be interested in how you find the 59 Quick Wax to work. Please let us know.

Glad in New England we do not have whatever the black spots being referred to is.

In my post, I was only referring to water stains needing to be removed.

2018 Oliver Elite II, Twin Bed, Hull #354 

2024 RAM 1500, 4 x 4; Gas. 5.7L V8 Hemi MDS VVT Torque; 3.21 rear axle ratio

Maine 

 

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13 hours ago, dewdev said:

rideandfly: I would  be interested in how you find the 59 Quick Wax to work. Please let us know.

Glad in New England we do not have whatever the black spots being referred to is.

In my post, I was only referring to water stains needing to be removed.

Will do on the 59 Quick Wax.

We have not encountered artillery spores. Hope Bill will tell us how he resolves the issue.

Bill #75 LE2

 

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Hello Oll,

 I’ve been working in the marine industry for 40 years. gelcoat is very similar to paint in it’s required care. CUT, POLISH, WAX !! A heavily oxidized gelcoat will require cutting with sponge abrasive wheels. If you have not had experience with this , it would be best to learn from someone experienced. There are excellent YouTube tutorials on this if you are feeling too cheap to pay someone or, honestly want to learn yourself . Most important are cutting implement abrasive grades, polisher speed adjustment during passes and pressure applied to surface as you go. Polishing a new paint/gelcoat or an old weather/industrial impurity/sun damaged finish is an acquired, hands on skill. The most forgiving victim would be an auto/boat that is moderately oxidized. Find an old car that needs a polish and go to it. It can only look better, so you won’t have to worry too much about barking up an $80,000 trailer.

 After all of these years polishing boats and cars, I have come to be unimpressed with highly specialized products. Any product that promises high gloss without your flesh as a toll, is packed with disproportionate amounts of petroleum products like oil or grease (most likely salad oil from the local grocer). While some amount of these two ingredients are normal and desired, too much is harmful when left on and especially when activated by U.V. Influence. (Think Amorall after two weeks in the sun) 

I recently bought an Ollie elite used (02/10/2022) from a guy that neglected to clean and care for the exterior finish (gel coat) and had it stored outside in Albuquerque N.M. The finish had a good bit of oxidation on the upper end sections. The gel coat was slightly yellow and not reflective at all (moderate oxidation). I chose to do a 4 stage polish restoration on these two areas , 3 stage on the upper sides and a 2 stage on the lower tub portion of ol’ Boondock. I use a dual action orbital polisher from Harbor freight (@$100) combined with the foam polishing pads in the specified cutting abrasives and the Maguire cut, polish and wax in their respected levels of abrasion for cut and polish. It is important to match the pad and polish cut levels. All of these items can be purchased at Harbor freight. The complete works for a 4 stage polish will cost about $300.00 . A 1 time detail (polish and wax, no cutting) for your Ollie by a competent detailer will run you $400-800 if they are any good and experienced. A 4 stage polish on an 18’ trailer takes 2 full days, a 2 stage ,1 full day. Ask yourself how much you would charge for your two days of experienced, dirty, manual labor.

 I’m only stating my experience here. If you disagree, tell your life mate, not me. Maintaining expensive, shiny things is expensive and time consuming. The maintenance part of acquiring and maintaining these things “comes with the dinner”.

have a great day, B

 

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2008 Ram 1500 4 × 4

2008 Oliver Elite, Hull #12

Florida and Western North Carolina, or wherever the truck goes....

400 watts solar. DC compressor fridge. No inverter. 2 x 105 ah agm batteries .  Life is good.


        
 

 

 

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