Need new coroplast for the entire camper underbelly

ewarnerusa · 06-19-2017, 09:25 PM

I lost the entire coroplast liner that enclosed my camper's underbelly this weekend. I think the root cause was from some axle work I had done two years previous. I noticed then that they didn't fully reattach the coroplast to the frame very well at the axles. I had always meant to button it up better but never got around to it....

While driving to the destination this weekend I was passed by a car that rolled their window down and gave me the signal that something was up. I pulled over and found about the third of the coroplast liner still attached to the very rear of the camper and dragging on the ground. The entirety of the rest of it was completely gone! Luckily it didn't tear any wiring out or propane lines. It did tear the handle off of my gray water dump valve. I had to screw a long wood screw in as a hack to get the tank dumped.

So has anyone else replaced the entire liner before? Dealer or DIY project? Cost? Thanks.

donzinger · 06-20-2017, 04:12 PM

Can't offer to much help in this area, but Home Depot does sell sheets of it. Might be able to make contact with the manufacturer to see if they offer other sizes or a roll...best of luck.

ewarnerusa · 06-20-2017, 04:23 PM

Thanks. I am finding via internet that you can get it in 4'x8' sheets from hardware stores. Also recommendations to reach out to sign shops for potentially better prices

RVNevada · 06-22-2017, 06:53 PM

ewarnerusa, before you place it back together, nows the time to take pictures of everything, so you know where something is, before opening the whole thing again, if it comes to that...

donzinger · 06-23-2017, 10:54 AM

I posted this in another thread - seems appropriate here too. It is the tape for use on that material:

Search eBay for Flex-Mend (FM-4108T) RV Belly Tape - this is product made for the chloroplast belly we have on these rigs. Works fantastic!

ewarnerusa · 07-25-2017, 07:05 PM

OP Update.
Nothing has been fixed yet, but I have ventured into Home Depot to find 4'x8' sheets of coroplast for ~$22 ea. I had not bothered calling my RV dealer just assuming that this would be a big $$$ item from them. Turns out, based on a phone call anyway, that they have it in a 70" roll that they sell by the foot for $7/ft. This is very reasonable and likely the route I'll go.

MartyG · 07-25-2017, 11:39 PM

Quote:

Originally Posted by ewarnerusa

OP Update.
Nothing has been fixed yet, but I have ventured into Home Depot to find 4'x8' sheets of coroplast for ~$22 ea. I had not bothered calling my RV dealer just assuming that this would be a big $$$ item from them. Turns out, based on a phone call anyway, that they have it in a 70" roll that they sell by the foot for $7/ft. This is very reasonable and likely the route I'll go.

Check the math. 4x8 is 32 sq ft, so a sheet that cost cost $22 is .69, or 69 cents per sq ft. The roll, each ft of length is 5.8 sq ft, so each sq ft cost $1.21 Perhaps more pertinent, your main underbody is probably 8 ft wide. 70" doesn't help much. I'd use a sheet of 4x8, placed left to right, for each 4 ft of trailer length.

snakebitten · 07-26-2017, 01:52 AM

Marty knows his math!

Good catch.

ewarnerusa · 07-26-2017, 12:11 PM

I realize it's more, but only slightly and surprisingly not a lot more since it is from a dealer. Plus I'd rather have a single continuous sheet like it was originally. Multiple pieces makes me worried it would catch air again and pull off again. When I measured previously the frame width was roughly 6'. So I'll have to remeasure to see if it was really 70". I suspect so, probably a standard width.

ewarnerusa · 07-26-2017, 05:48 PM

But to put it another way, my rough measurement of the size of the old coroplast is 6'x24'. I'd need 6 sheets of 4x8 to cover that, so 6*$22 = $132.
Assuming 70" width works for me, that's 24*$7 = $168.

So that's $36 more to get a single clean seamless sheet vs cobbling 4x8 sheets together. Seems worth it to me.

ewarnerusa · 08-14-2017, 04:31 PM

Finally got around to getting the tape measure out and crawling around under my camper to do some measuring. It is indeed a 70" wide sheet of coroplast that came off so this must be an industry standard. The sheet does not go from edge to edge of the camper underbelly, but rather spans the distance between the frame rails. 70" does the trick nicely. So I'll head to the RV dealer and get what I need. It exactly 24' lengthwise, but I'll probably get an extra foot for contingency.

MartyG · 08-14-2017, 04:38 PM

Good to know! Thanks for the update!

ewarnerusa · 08-14-2017, 04:43 PM

Definitely. Just called the shop and of course they are running low on it! But more of it is apparently on order and I can check back in a week or so.
I noted that my now-exposed gray and black tanks are stamped at 37 gallon capacity each rather than the 50 gallons that the spec sheet indicated. Good to know I suppose! And as I mentioned earlier, the heated underbelly appears to be from radiant heat from ductwork and a quarter sized hole at the underside of the furnace that represents the heat duct pointed down there.

wildwest450 · 08-14-2017, 10:07 PM

Quote:

Originally Posted by ewarnerusa

And as I mentioned earlier, the heated underbelly appears to be from radiant heat from ductwork and a quarter sized hole at the underside of the furnace that represents the heat duct pointed down there.

I've always thought that the "heated underbelly" was yet another form of RV false advertisement. I don't even use my furnace, I can heat nicely with a small electric heater. I guess i'll stay home when it gets down below freezing.

It would probably be more efficient to put the heater under the camper and let the warm air come up through the floors.

ewarnerusa · 08-15-2017, 01:46 PM

I actually think the underbelly probably does get some useful heat from this. The vent is tiny but the air space down there is also quite small compared to the interior. It only needs to be warmed enough to be above freezing, not room temperature like the camper interior. And the radiant heat from the warm ductwork would contribute a lot.

But yeah, I wouldn't count on it to keep up during a deep freeze. I don't winter camp and would probably avoid the plumbing system completely if I did. It takes a lot of effort to keep water liquid in a mountain winter!

Occupant5143 · 08-15-2017, 04:14 PM

Quote:

Originally Posted by ewarnerusa

I noted that my now-exposed gray and black tanks are stamped at 37 gallon capacity each rather than the 50 gallons that the spec sheet indicated. Good to know I suppose!

That is good to know since it tends to confirm my observation that the fresh water tank only accepts 37 gallons. I guess the 50 gallon figure is typical marketing magic.

ewarnerusa · 08-15-2017, 04:59 PM

I didn't check my fresh tank but I'll try before it is covered up again. Mine does appear physically larger than the waste tanks though.

ewarnerusa · 07-23-2018, 08:42 PM

Follow up, project done. The coroplast was around $170 from the dealer. The install took me several of weekends when I could devote some time to it. I learned some tricks along the way that I'll hopefully never have to try again. Main thing being to use jacks or blocks or whatever is handy to hold the sheet up against the camper underbelly. My original plan was to just start at one corner and keep it aligned as I progressed with screwing the new sheet back on. Eventually I'd use other means to hold up the coroplast but I didn't think it would be necessary at first. I should have just done it from the start, it would have helped make it easier to keep aligned as I progressed because despite my best efforts it still got out of alignment as I progressed. What I ended up using was a stool beneath the camper with bottle jack on top of the stool and then a roughly 2'x4' sheet of plywood on top of the bottle jack. I'd raise the jack and plywood until it pressed the coroplast up so all sag was removed. Then I'd start screwing it onto the frame.

CSCLARK · 07-23-2018, 11:06 PM

Hey Ed any pics of the project? How did you end up securing? Was it preciously pop rivets?

**wahoonc** · 07-23-2018, 11:29 PM

Quote:

Originally Posted by ewarnerusa

Follow up, project done. The coroplast was around $170 from the dealer. The install took me several of weekends when I could devote some time to it. I learned some tricks along the way that I'll hopefully never have to try again. Main thing being to use jacks or blocks or whatever is handy to hold the sheet up against the camper underbelly. My original plan was to just start at one corner and keep it aligned as I progressed with screwing the new sheet back on. Eventually I'd use other means to hold up the coroplast but I didn't think it would be necessary at first. I should have just done it from the start, it would have helped make it easier to keep aligned as I progressed because despite my best efforts it still got out of alignment as I progressed. What I ended up using was a stool beneath the camper with bottle jack on top of the stool and then a roughly 2'x4' sheet of plywood on top of the bottle jack. I'd raise the jack and plywood until it pressed the coroplast up so all sag was removed. Then I'd start screwing it onto the frame.

We use 2x4s and a couple of screw jacks..

Aaron

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