Scamp bottom of trailer--should I undercoat?

[Carol H]

Originally Posted by Darral T.

BillE, my Scamp's underside OSB was coated in polyester resin (fiberglass) My Scamp is nearly 6 yo and still looks fine underneath. I keep a watchful eye one it.

My 23 year old Scamp is the same - coated on underside with fiberglass resin and still looks clean and new although it has down lots of travels in rainy season and the winter months.

[Kai in Seattle]

Originally Posted by gordon2

I also wondered (and previously asked) about the cutouts, esp the one for the shower and commode drains. It appears that the cuts are made after the wood is treated, so the cut edges are then unprotected. I think its a reasonable idea to try and seal the cut edges.

Pretty sure this has been a cause of rot / floor replacement in the amerigos...they add a toilet after the first sale and don't finish the cut-out edges..............and so it begins.

[Roger H]

Originally Posted by Darwin Maring

You can not go wrong by undercoating. Should you not do it and something happen then you will kick yourself in the butt for not doing it.

What "something happening" are you concerned about specifically, Darwin?

While undercoating a Scamp won't be a disaster, there are a number of good reasons why NOT to do it... some of which have to do with water draining and the OSB drying naturally; some of it has to do with making necessary repair disassembly afterwards a gooey, nasty mess, and some has to do with the undercoat hiding rust that you might have otherwise prevented.

Undercoating in automotive applications isn't as necessary as it was twenty years ago, but I can't see any reason TO do it on a Scamp, and a half-dozen reasons NOT to.

[Darwin Maring]

Well, he is somewhat worried or he wouldnt have asked the question.
A professional sprayed on product like they do on pickups would sure be a preserative and extend the life of the unit.

Preconditioning of the frame would be even better before application to insure against undetected rust.

There are many posts each year on this site concerning rusted frames and rotted flooring.

If the owner has concern about this happening, the proper application of a spray on product would be something to think about.

http://www.eastwood.com/paints/rust-solutions.html

[redbarron55]

Personally I would seal the penetrations for the drains etc. and leave the bottom of the floor alone.
The polyester resin is permeable to water and this is why if the water sits pooled on top of the polyester resin covering the floor it will rot.
The water on the bottom will dry out and not damage the wood.
Seal the openings and leave the rest of the bottom alone.
If you wanted to worry about something you might think about caulking alonf the frame to try to keep the water from standing between the frame and floor.
The permeability of the polyester resin compared to the epoxy is why I chose to spend the extra money on it to glass the floor, top and bottom.

[Roger H]

Originally Posted by Darwin Maring

Well, he is somewhat worried or he wouldnt have asked the question.
A professional sprayed on product like they do on pickups would sure be a preserative and extend the life of the unit.

How would it extend the life of the unit? What, exactly are you trying to preserve?

If you're talking about a bedliner spray, that would be problematic on the bottom of a trailer. It's hard and would seal bolt and screw heads in so they can't be removed. It would also turn the trailer floor into a tub; not such a good idea.

Originally Posted by Darwin Maring

Preconditioning of the frame would be even better before application to insure against undetected rust.

Frame rust can be stopped for some time with POR-15 and a good coat of Rustoleum black over that. But if you cover it with undercoat and it starts rusting under the layer of undercoat, it can be neither easily seen nor, once found, easily treated because of the oily undercoat.

Originally Posted by Darwin Maring

There are many posts each year on this site concerning rusted frames and rotted flooring.

Rust you can see can be dealt with appropriately and pretty easily. Of those many posts about floor rot, how many claimed that the floor rotted out from below? Probably none. Trailer floors don't rot from the underside up, they rot from the top down where water pools on TOP of the wood and soaks it.

As I said in a post above, I can't think of a single good reason to undercoat a wood-floored trailer, but I can think of a number of really good reasons not to.

[Raz]

If you wanted to worry about something you might think about caulking along the frame to try to keep the water from standing between the frame and floor.
.

My previous camper used self drilling scews to fasten the floor to the frame. Within four years most of those screws were rusted so bad they could be pulled out by hand. Apparently water had gotten between the floor and the frame. I believe Scamp uses similar screws yet I have never heard anyone mention this issue. Anyone pulled a screw and found rust ? Raz

[redbarron55]

My old frame had several points where the holes had rusted and no screws made contact with the steel. This was where the floor was originally mounted, but had since been replaced with a "new piece of plywood so I cannot speak about what transpired.




You can see the holes mentioned in the above pictures along with the rusted out space where the shell contacted the frame on the driver's side.

However this is from a much abused trailer and a 1986 vintage.
It now had a new frame from the cutoff part extended about another 18" to reduce the load on the hitch and make the trailer more stable. This extends the bend to just outside the front of the shell.
The frame was painted with zinc rich epoxy primer to hopefully resist new rust.

[Paul O.]

To reiterate - if the bottom of the trailer gets wet from splashed rain, it will dry. An undercoat with imperfections, which are inevitable, will create traps and keep it wet longer and may hide problems. I'd say no to undercoating.

[Kai in Seattle]

Originally Posted by P. Raz

My previous camper used self drilling scews to fasten the floor to the frame. Within four years most of those screws were rusted so bad they could be pulled out by hand. Apparently water had gotten between the floor and the frame. I believe Scamp uses similar screws yet I have never heard anyone mention this issue. Anyone pulled a screw and found rust ? Raz

When we got our 73 amerigo home last fall, six out of eight bolts that held shell to frame were rusted through; the other two were rusted down to a narrow core.

We'd been thinking of putting a rubberized truck bed lining over the glass (tub) bottom as protection against rock chips...but it sounds like weep holes in the low spots inside would be a good idea, too.

[CampyTime]

I've read several posts here about the POR 15. Heard of this before here but wonder...

My scamp's a 2012. Someone mentioned a few years down the line of ownership that this is a good idea. Does this entail getting under trailer with a stuff wire brush, brushing off flaking and crud and then hand painting on, followed by say a hand painting of Rustoleum gloss black?

Can't see how a rattle can would be practical or neat underneath, nor would I want to overspray a lot on the resin coated OSB. Just curious, that's all.

Btw, I live in NY but trailer is cold stored indoors in winter. Frame still looks good as I recall, but thinking toward future maintenance.

Cheers,
Wendy


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[Roger H]

Originally Posted by CampyTime

I've read several posts here about the POR 15. Heard of this before here but wonder...

My scamp's a 2012. Someone mentioned a few years down the line of ownership that this is a good idea. Does this entail getting under trailer with a stuff wire brush, brushing off flaking and crud and then hand painting on, followed by say a hand painting of Rustoleum gloss black?

Can't see how a rattle can would be practical or neat underneath, nor would I want to overspray a lot on the resin coated OSB. Just curious, that's all.

Btw, I live in NY but trailer is cold stored indoors in winter. Frame still looks good as I recall, but thinking toward future maintenance.

Cheers,
Wendy


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Yep. Just like that.

I have an '07 Toyota FJ Cruiser. The rear frame under the back door is notorious for rusting as are the rear frame rails behind the axle. Every couple of years, I crawl under it and do the deed. The first time, I borrowed my buddie's hoist at his auto shop. This year, I flaked a little... and dispensed with the brush. I just crawled under it in my driveway and used rattle-can Rustoleum rust reducer (essentially the POR 15 part) and then rattle can sprayed everything with Rustoleum heavy rust primer (the red stuff) and then re-sprayed it with flat black Rustoleum as a top coat.

So far, so good.

[CampyTime]

Thanks Rog. So after the rust reformer, you still need the primer before painting? So the reformer only converts the rusty crap to a paintable surface, necessitating the primer. Got it.

So this is just something to keep an eye on right? Not a go out and do it preventative maintenance thing unless it needs doing? Like I said, frame looked good, probably only has a tad of surface oxidation. But I'll inspect more closely in spring.

Thanks again. Just looked up the POR and Tis not cheap.


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[CampyTime]

Also, should a degreaser be used on frame first or no?


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[Donna D.]

You can apply all kinds of rust preventive stuff to bolts and frame issues.. and do it over and over and over again every year. OR, you can do it "once and done." POR-15... all the way


POR-15 isn't cheap or simple to apply.. what is your time, effort and your asset worth?

[Borrego Dave]

Applying a protective coating to your frame before any rust starts is a good thing. I do have to ask those of you that live in areas that are prone to rust from salt ect, if just coating three sides of your frames is a + or - as the top edge has only the factory paint and you can't see any rust problems starting. I do remember one member here doing a shell off resto, coating the frame and also adding a thin material between the shell and frame to cut down any chafing.

[Paul O.]

The pictures in post #28 illustrate the problem. I am pretty sure that my Scamp does not have any sealer (mastic) between the floor and the frame. I intend to keep the rust in check by spraying those gaps with either oil or WD40, which should wick in.

I also remember somebody putting the sealer between the frame and the floor when restoring their rig.

[Roger H]

Originally Posted by Borrego Dave

Applying a protective coating to your frame before any rust starts is a good thing. I do have to ask those of you that live in areas that are prone to rust from salt ect, if just coating three sides of your frames is a + or - as the top edge has only the factory paint and you can't see any rust problems starting. I do remember one member here doing a shell off resto, coating the frame and also adding a thin material between the shell and frame to cut down any chafing.

Dave, all you can do is what you can do. If you're starting from scratch on a frame-off resto, then of course it would be prudent to do the entire frame. If you're doing preventative on an existing frame, you'll only be able to do three sides.

You have to keep this in perspective though... what you're doing is retarding the aging process... but a torsion axle's design life is only about 15 years, and if you get that out of it, you've done well. How many folks keep a car more than ten or fifteen years?

These trailers were never meant to have forty years' worth of use out of them... but they're getting it now. ANY trailer you can get twenty years out of is amazing. Most stickies are junk in less than 10 years anywhere that it rains regularly. Unless you store it inside on blocks and maintain it meticulously, figure on a frame-off resto if you're going to keep it past that.

So you're not going to extend the life of the trailer past its design-life... you're just trying to keep it going until it's normal end-of-life cycle...

[CampyTime]

All you can do is what you can do. I agree that this is true.

I just went to POR 15 website to do more reading on this product. They actually recommend a 3 step process of their products: water based degreaser, metal prep and then the POR rust reformer.

I get the degreaser part I guess (road grease) but not sure if the metal prep would be necessary on a newer trailer? Talks about etching the bare metal so the POR 15 adheres better.

Would someone who has used this 3 step process chime in for me? I just am hoping to learn as much as possible through others experiences as I have the POR 15 site I can read anytime.

Sounds like the rustproofing is something I should do before a problem arises.

Thanks for your thoughts.

Wendy


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[Raz]

It's very easy to say use POR 15. On a body off frame, no problem. But how many who recommend it have actually done a frame on their backs under the trailer. After spending some time reading the can at the local auto parts store I decided against it. Paint can be removed with thinner. This stuff has to wear off. I have no desire to go through life looking like a Holstein.

Dave you are correct. You can't do the top without removing the body. If you have a tubular frame you can't do the inside even with the body off. Basically you do what you can. As to salt, by May it's gone from the roads. Not much open for camping earlier than that anyway. If that were not the case, you would probably need a new frame every 10 years or so. Raz