Texman 182g Mods - R-pod Owners Forum

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texman

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Topic: Texman 182g Mods
Posted: 25 Feb 2019 at 9:13am

TexMan 2015 182g
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offgrid

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Posted: 25 Feb 2019 at 11:39am

Thanks for the update texman. What you've done so far doesn't look that bad to me not having seen the process of getting it to that point. That landscape cloth is strong stuff, it really should hold up to highway speeds. Of bigger concern is if the insulation board falls down and there is a gap where air gets in.

If you do decide to start over with foam I wouldn't worry about the mess, especially if you have the tank out. I foamed the perimeter of my house from underneath and wore old clothes that I keep around for that purpose. Definitely wear goggles, a hair cover, and gloves, and do it outside on a warm day on a sheet of plastic that you will trash afterwards. And don't ever try to clean the stuff off anything until it fully cures Thumbs Down

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

lostagain

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Posted: 25 Feb 2019 at 4:45pm

That looks like a heck of a lot of work Texman. You make me feel lazy.

Is there something you are going to replace the duct tape with? That stuff looks like the weak link in the package. Also, what if you bought a flat piece of sheet galvanized sheet metal that you could cover the whole thing up with and screw it fore and aft to the metal that holds the tank or use the TPO you already have? That way, you'd reduce the windage on the cloth. The it's made to be wet in the dirt, so it could be there for a very long time if it doesn't get ripped off by the wind.

Never leave footprints behind.
Fred & Maria Kearney
Sonoma 167RB
Our Pod 172
2019 Ford F-150 4x4 2.7 EcoBoost

texman

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Posted: 25 Feb 2019 at 5:18pm

Tape was just to hold the fabric while installing. No function now. The fabric is held now by compression against the pod floor and also by the weight of the tank on the tank mounting arms.

TexMan 2015 182g
2018 Sequoia
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texman

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Posted: 25 Feb 2019 at 7:50pm

I am looking into the closed cell foam. I am reading that it does not stick to polyethylene. That is what the water tank is made of correct? Any thoughts on that?

TexMan 2015 182g
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offgrid

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Posted: 26 Feb 2019 at 6:45am

Yes, the tank is polyethelene (PE). You won't find anything that bonds well to PE. It is one of several commonly used low surface energy (LSE) polymers. LSE in practice means that the chemical makeup of the materials doesn't allow adhesives wet out when applied to them. Others LSE polymers include TPO, polypropylene, polyvinyl fluoride (aka Tedlar), and everyone's favorite PTFE (aka Teflon). PE is great for something like a water tank because stuff doesn't stick to the inside of it. But not so good when you want to attach something to it.

It is possible though to adhere things to PE and other LSE's if a proper surface treatment is applied first and you're not expecting to form a really strong mechanical bond (like say if you try to glue two sticks of plastic together and bend the joint).

In the case of foaming a PE tank the bond doesn't need to be really strong but you need some bond strength. So some surface treatment is in order. There are two options I know of: flame treatment and primers.

I fixed a couple cracks in my PE Hobie kayak by stop drilling the craks, then flame treating the crack surfaces then using West Systems gflex epoxy. I got very good adhesion, that was 2 years ago and the cracks have not reopened.

In my former work in solar module design and manufacturing we used Tedlar (PVF) as the backsheet material. Tedlar is also the stuff you see on the interior walls of commercial aircraft, because its easy to keep clean. We bought our Tedlar flame treated on one side and got great adhesion when we laminated the modules, good enough to last 30-40 years outside. If the maunfacturing folks screwed up and used the non flame treated side the Tedlar backsheets would peel right off by hand.

So I'm a big fan of flame treatment. You are not looking to melt the surface, just dull the shiny finish. You can also check whether its done the job by seeing if water sheets out on the flame treated surface significantly better than the non flame treated side. That is a sign that you've activated the PE surface and you'll get decent adhesion. For sure though try a small area first to be sure you're getting adhesion to the foam before going to the trouble of flame treating and spraying the whole tank.

Here is a 3M article explaining all this in more detail. Of course, they are trying to sell you on their primers, which is fine, you can look into that too, but also take a look at the graph showing improvement from simple surface flame treatment.

https:///multimedia.3m.com/mws/media/755526O/innovations-in-bonding-to-low-surface-energy-white-paper.pdf

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

texman

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Posted: 26 Feb 2019 at 10:42am

good info thanks.

After a quick read it sounds like the flame treatment is really the only plausible way. The working times are way to short on the treatments to get everything done in that window of time. The problem i see with my current situation as well as spraying the tank with foam when removed is that the upper third of the tank is un-insulated. Reason is, if the tank is completely covered with either substance while removed, it will not fit back into the framing that supports it. Therefore, my thinking is that the best would be to spray the tank while it is mounted to the pod and cover the upper 1/3rd and the metal framing. That would be the best way i think. It will be a problem at ends of the tank since there is only about 2" on either end between end of tank and the trailer frame. that would have to be filled with foam as best you can i think.

meanwhile, back to my situation. as i just said, the best approach to this is spraying the tank while installed. the tank is apox 15 sf by my calcs of surface area excluding the top. so if i have 1/3 of the sides unprotected that is 2.23 sf ft or 15%. That is where i am at now. So is that good enough to test with for awhile? i think so at this point, especially since it is the top 1/3 right next to the floor that is heated on the opposite side. The real question for me now is will my currently applied materials withstand highway speeds, rainy highways, etc. and not fly off on the interstate and cause who knows what when a 10 sq ft piece of insulation and landscape fabric appear out of nowhere to a driver behind me? i am not confident enough to try it in its current state.

So i have to cover what i have with the TPO (or something else) which is doable i think or start over and go to foam. But at least i wouldn't really have to worry about the foam coming loose if the tank was flame treated and had a proper bond and i could insulate that upper third. I dont think the upper 1/3 or 15% is going to make a noticeable and measurable difference really, just trying to talk through all this and make sense of it and give you folks something to read. Especially if i wrap it again like i said.

Still contemplating but i am leaning towards trying to at cover what i have and go camping. Smile

TexMan 2015 182g
2018 Sequoia
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offgrid

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Posted: 26 Feb 2019 at 10:58am

I think going ahead with what you have for insulation and getting everything setup correctly and working is a good idea. That way you can get a handle on how much propane you’re using and decide how carefully you need to insulate going forward. You’re going to run out of cold weather soon to test with, so you might have to set the thermostat a little higher so you can maintain a similar temp differential to what you expect when it’s colder. Fill and weigh your propane tank, run for 24 hours, weigh it again. You might find the propane use is lower than we think so you can get by with less insulation.,

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

texman

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Posted: 26 Feb 2019 at 5:27pm

does flame treatment to polys have a working time limit? Would the foam need to be applied immediately after flame treatment to achieve correct bonding?

TexMan 2015 182g
2018 Sequoia
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Motor7

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Joined: 09 Jan 2019
Location: E. TN
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Posted: 26 Feb 2019 at 5:56pm

Would not a insulated belly pan from the front of the pod to the rear be a better way to go? Something that could be dropped to service the underbelly components?

Even though I threw this out there, I already have an issue with my underbelly BAL spare tire carrier, so it would not work for me unless I removed it.

2016 R-Pod 176T

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texman Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 24 Jul 2014 Location: TeXas Online Status: Offline Posts: 446	Topic: Texman 182g Mods Posted: 25 Feb 2019 at 9:13am

	TexMan 2015 182g 2018 Sequoia TexManMods

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 25 Feb 2019 at 11:39am
	Thanks for the update texman. What you've done so far doesn't look that bad to me not having seen the process of getting it to that point. That landscape cloth is strong stuff, it really should hold up to highway speeds. Of bigger concern is if the insulation board falls down and there is a gap where air gets in. If you do decide to start over with foam I wouldn't worry about the mess, especially if you have the tank out. I foamed the perimeter of my house from underneath and wore old clothes that I keep around for that purpose. Definitely wear goggles, a hair cover, and gloves, and do it outside on a warm day on a sheet of plastic that you will trash afterwards. And don't ever try to clean the stuff off anything until it fully cures .
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2587	Posted: 25 Feb 2019 at 4:45pm
	That looks like a heck of a lot of work Texman. You make me feel lazy. Is there something you are going to replace the duct tape with? That stuff looks like the weak link in the package. Also, what if you bought a flat piece of sheet galvanized sheet metal that you could cover the whole thing up with and screw it fore and aft to the metal that holds the tank or use the TPO you already have? That way, you'd reduce the windage on the cloth. The it's made to be wet in the dirt, so it could be there for a very long time if it doesn't get ripped off by the wind.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost

texman Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 24 Jul 2014 Location: TeXas Online Status: Offline Posts: 446	Posted: 25 Feb 2019 at 5:18pm
	Tape was just to hold the fabric while installing. No function now. The fabric is held now by compression against the pod floor and also by the weight of the tank on the tank mounting arms.
	TexMan 2015 182g 2018 Sequoia TexManMods

texman Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 24 Jul 2014 Location: TeXas Online Status: Offline Posts: 446	Posted: 25 Feb 2019 at 7:50pm
	I am looking into the closed cell foam. I am reading that it does not stick to polyethylene. That is what the water tank is made of correct? Any thoughts on that?
	TexMan 2015 182g 2018 Sequoia TexManMods

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 26 Feb 2019 at 6:45am
	Yes, the tank is polyethelene (PE). You won't find anything that bonds well to PE. It is one of several commonly used low surface energy (LSE) polymers. LSE in practice means that the chemical makeup of the materials doesn't allow adhesives wet out when applied to them. Others LSE polymers include TPO, polypropylene, polyvinyl fluoride (aka Tedlar), and everyone's favorite PTFE (aka Teflon). PE is great for something like a water tank because stuff doesn't stick to the inside of it. But not so good when you want to attach something to it. It is possible though to adhere things to PE and other LSE's if a proper surface treatment is applied first and you're not expecting to form a really strong mechanical bond (like say if you try to glue two sticks of plastic together and bend the joint). In the case of foaming a PE tank the bond doesn't need to be really strong but you need some bond strength. So some surface treatment is in order. There are two options I know of: flame treatment and primers. I fixed a couple cracks in my PE Hobie kayak by stop drilling the craks, then flame treating the crack surfaces then using West Systems gflex epoxy. I got very good adhesion, that was 2 years ago and the cracks have not reopened. In my former work in solar module design and manufacturing we used Tedlar (PVF) as the backsheet material. Tedlar is also the stuff you see on the interior walls of commercial aircraft, because its easy to keep clean. We bought our Tedlar flame treated on one side and got great adhesion when we laminated the modules, good enough to last 30-40 years outside. If the maunfacturing folks screwed up and used the non flame treated side the Tedlar backsheets would peel right off by hand. So I'm a big fan of flame treatment. You are not looking to melt the surface, just dull the shiny finish. You can also check whether its done the job by seeing if water sheets out on the flame treated surface significantly better than the non flame treated side. That is a sign that you've activated the PE surface and you'll get decent adhesion. For sure though try a small area first to be sure you're getting adhesion to the foam before going to the trouble of flame treating and spraying the whole tank. Here is a 3M article explaining all this in more detail. Of course, they are trying to sell you on their primers, which is fine, you can look into that too, but also take a look at the graph showing improvement from simple surface flame treatment. https:///multimedia.3m.com/mws/media/755526O/innovations-in-bonding-to-low-surface-energy-white-paper.pdf
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

texman Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 24 Jul 2014 Location: TeXas Online Status: Offline Posts: 446	Posted: 26 Feb 2019 at 10:42am
	good info thanks. After a quick read it sounds like the flame treatment is really the only plausible way. The working times are way to short on the treatments to get everything done in that window of time. The problem i see with my current situation as well as spraying the tank with foam when removed is that the upper third of the tank is un-insulated. Reason is, if the tank is completely covered with either substance while removed, it will not fit back into the framing that supports it. Therefore, my thinking is that the best would be to spray the tank while it is mounted to the pod and cover the upper 1/3rd and the metal framing. That would be the best way i think. It will be a problem at ends of the tank since there is only about 2" on either end between end of tank and the trailer frame. that would have to be filled with foam as best you can i think. meanwhile, back to my situation. as i just said, the best approach to this is spraying the tank while installed. the tank is apox 15 sf by my calcs of surface area excluding the top. so if i have 1/3 of the sides unprotected that is 2.23 sf ft or 15%. That is where i am at now. So is that good enough to test with for awhile? i think so at this point, especially since it is the top 1/3 right next to the floor that is heated on the opposite side. The real question for me now is will my currently applied materials withstand highway speeds, rainy highways, etc. and not fly off on the interstate and cause who knows what when a 10 sq ft piece of insulation and landscape fabric appear out of nowhere to a driver behind me? i am not confident enough to try it in its current state. So i have to cover what i have with the TPO (or something else) which is doable i think or start over and go to foam. But at least i wouldn't really have to worry about the foam coming loose if the tank was flame treated and had a proper bond and i could insulate that upper third. I dont think the upper 1/3 or 15% is going to make a noticeable and measurable difference really, just trying to talk through all this and make sense of it and give you folks something to read. Especially if i wrap it again like i said. Still contemplating but i am leaning towards trying to at cover what i have and go camping.
	TexMan 2015 182g 2018 Sequoia TexManMods

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 26 Feb 2019 at 10:58am
	I think going ahead with what you have for insulation and getting everything setup correctly and working is a good idea. That way you can get a handle on how much propane you’re using and decide how carefully you need to insulate going forward. You’re going to run out of cold weather soon to test with, so you might have to set the thermostat a little higher so you can maintain a similar temp differential to what you expect when it’s colder. Fill and weigh your propane tank, run for 24 hours, weigh it again. You might find the propane use is lower than we think so you can get by with less insulation.,
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

texman Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 24 Jul 2014 Location: TeXas Online Status: Offline Posts: 446	Posted: 26 Feb 2019 at 5:27pm
	does flame treatment to polys have a working time limit? Would the foam need to be applied immediately after flame treatment to achieve correct bonding?
	TexMan 2015 182g 2018 Sequoia TexManMods

Motor7 Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 09 Jan 2019 Location: E. TN Online Status: Offline Posts: 196	Posted: 26 Feb 2019 at 5:56pm
	Would not a insulated belly pan from the front of the pod to the rear be a better way to go? Something that could be dropped to service the underbelly components? Even though I threw this out there, I already have an issue with my underbelly BAL spare tire carrier, so it would not work for me unless I removed it.
	2016 R-Pod 176T