Flex seal on the wooden underbody

[Mitten Mitsie]

My father suggested painting the wooden bottom of my 1972 Trail Mite with flex seal. Anyone do this? Anyone think this is a bad idea?

[Julie in Montana]

I have an ‘83 Scamp that I’ve renovated. I debated using a similar product when I was starting, but decided to follow this mind set: try to keep the moisture from penetrating the top of the OSB board by sealing it well, but don’t seal the moisture inside, let it evaporate out of the open bottom.

I’m a few years into my renovation, and so far, that theory is working. I live in a relatively arid climate in Montana, so there may be other opinions, but this has worked for me. Good luck!

[Darwin Maring]

Originally Posted by Julie in Montana

I have an ‘83 Scamp that I’ve renovated. I debated using a similar product when I was starting, but decided to follow this mind set: try to keep the moisture from penetrating the top of the OSB board by sealing it well, but don’t seal the moisture inside, let it evaporate out of the open bottom.

I’m a few years into my renovation, and so far, that theory is working. I live in a relatively arid climate in Montana, so there may be other opinions, but this has worked for me. Good luck!

What if the wood is totally dry and you seal both sides?

[mosquito13]

Originally Posted by Mitten Mitsie

My father suggested painting the wooden bottom of my 1972 Trail Mite with flex seal. Anyone do this? Anyone think this is a bad idea?

I have used pot 15 on several ply projects. Made a carb spacer/heat barrier for my 440 engine. Exposed to race fuels for six years no issues. I diluted first coat by half with thinner to get more penetration , followed with a second un thinned coat. Recently did the 3/4 ply of the bed of my step side pickup on the road side. I did the metal frame of my camper with same product. The POR15 web site talks about wood applications, though it was designed as a rust encapsulator.
I got a couple cans of flex seal from habitat for humanity resale shop. So I have know idea how old the product was. I sprayed the exterior of three new prefill sandbags hoping to get a full hurricane season out of them. Let them dry then filled and stitched close. The seal delaminated from the bags in three months. Pretty extreme conditions , but enough for me not to want to use the stuff again. BTW I found a great product for tarps/sandbags and like. Egrolastic roof paint. NOT for your application but extends life of plastic fabrics in sun by x3 times.

[Julie in Montana]

The OSB floor on my Scamp was dry when I got it, but had a couple of spots that had suffered slight damage from previous moisture. I replaced one spot totally (under the ice box area) with new 3/4” plywood. After doing some research on docks and other materials exposed to continuous moisture, it made sense to me to seal the top side heavily, but do a lighter sealer on the exposed under belly side of the OSB, so that it can evaporate quickly.

[ordjen]

Originally Posted by Mitten Mitsie

My father suggested painting the wooden bottom of my 1972 Trail Mite with flex seal. Anyone do this? Anyone think this is a bad idea?

Speaking as a painting contractor; If you can't keep wood from getting wet, for goodness sake, don't do anything that prevents it from rapidly drying out! I fear that the rubber coating would trap in moisture. Wood that rapidly dries out does not readily rot. One of the copper or zinc containing wood preservatives might hold the rot at bay. Copper and zinc are toxic to plant life. Rot is basically fungus feeding of the cellulose in the wood fiber. The toxic metals kills the fungus.

I have never been a fan of OSB. Exterior grade plywood, or even regular plywood would do better.

[redbarron55]

When I replaced the floor in my Scamp 16 I used epoxy resin and fiberglass fabric to enclose the entire floor and to seal it to the shell. The floor is made up of several individual pieces that cover the rear, main floor, the sides and the front.
If you are not sealing with truly waterproof coverings you should leave a way for the moisture to escape and not remain to foster rot and degradation.
That said the factory probably does the worst job, spraying the underside of the floor with polyester resin and leaving the top of the OSB bare so that water can get in and stay.
By the way polyester is not a really good protector of wood as the many rotten stringers in fiberglass boats will attest.
If I were to do anything to the bottom of the trailer I think I would give it a nice coat of something like white anti-fungal primer and leave it at that.

[ThomasC]

Originally Posted by Mitten Mitsie

My father suggested painting the wooden bottom of my 1972 Trail Mite with flex seal. Anyone do this? Anyone think this is a bad idea?

When I replaced the floor on my old Styrofoam box a few years ago I sprayed the bottom with rubberized undercoat.

https://www.amazon.com/dp/B000M8PZ96...D=&*Version*=1

I had added some steel to the frame and that was well painted before the under coat. I think the under coat did a good job on the plywood. Flex seal should be very similar.

[ordjen]

Originally Posted by redbarron55

When I replaced the floor in my Scamp 16 I used epoxy resin and fiberglass fabric to enclose the entire floor and to seal it to the shell. The floor is made up of several individual pieces that cover the rear, main floor, the sides and the front.
If you are not sealing with truly waterproof coverings you should leave a way for the moisture to escape and not remain to foster rot and degradation.
That said the factory probably does the worst job, spraying the underside of the floor with polyester resin and leaving the top of the OSB bare so that water can get in and stay.
By the way polyester is not a really good protector of wood as the many rotten stringers in fiberglass boats will attest.
If I were to do anything to the bottom of the trailer I think I would give it a nice coat of something like white anti-fungal primer and leave it at that.

I find it amazing that these FG trailer manufacturers don't routinely seal both sides of the flooring with fiberglas, or at least a couple coats of resin. Time after time on this blog, the most common complaint is the floor that is rotting out. If nothing else, make it an extra cost option when ordered new! It is the Achilles Heal of FB travel trailers!

[Nick J]

There are a lot of products designed to seal out moisture DEFINITELY use one of them.

[Nick J]

BTW The bottoms of cargo containers are sealed with mastic like substance and they are made to last for years under extreme conditions. Probably available on Alibaba.com

[redbarron55]

Make sure what you use doesn't seal moisture IN.
The issues that have caused problems are mostly leaks from windows, refrigerators and plumbing inside and sitting and soaking into the floor.
Make sure that the top is sealed and the bottom will take care of itself as most water runs downhill.

[THene1713]

From my limited look/ memory, it is way overpriced*** (e.g. same $$for 10-ft flexseal tape vs 30-50-ft of competing?) so many other similar cheaper products just as good? *** Thos TV ads cost big $$

[David Tilston]

Originally Posted by THene1713

From my limited look/ memory, it is way overpriced*** (e.g. same $$for 10-ft flexseal tape vs 30-50-ft of competing?) so many other similar cheaper products just as good? *** Thos TV ads cost big $$

As a rule, if it is heavily advertised, I won’t buy it. I don't like commercials, and I refuse to pay for them, especially the media saturation style, like Flex Seal.

[Steve Outlaw]

Originally Posted by ordjen

I find it amazing that these FG trailer manufacturers don't routinely seal both sides of the flooring with fiberglas, or at least a couple coats of resin. Time after time on this blog, the most common complaint is the floor that is rotting out. If nothing else, make it an extra cost option when ordered new! It is the Achilles Heal of FB travel trailers!

Your profile states you are "looking" for a trailer. If you want one that you will never have to worry about anything wooden rotting, look at an Oliver. No frame to rust and need painting and no wood in any of the structure to rot.

[Bill Robison]

What you are stating seems to be common sense - and yet campers have dealt with rotting wooden floors for a very long time -- even if they were coated and/or sealed well top and bottom. I previously owned a 2008 EggCamper. I have had many face to face discussions with its original designer and owner, Jim Palmer. As I recall, Jim's plan was to eliminate this rotting wood using a different approach. He totally encased each wood flooring panel with resin. Perhaps he was correct in thinking that the 'weak link', which had been overlooked for many years is the open EDGES of the flooring allow the panels to absorb lots of moisture over time?

The moral of this story? Perhaps 'thinking' that sealing only the top and bottom of flooring panels is not sufficient to 'lock out' ALL moisture intrusion? The panel EDGES must also be sealed at the same time to prevent all moisture from leaks, atmospheric conditions, wet highways, etc - This creates a wrapped barrier, which stops moisture from entering the wood fibers, which then would allow major wicking and wood rot over time? Food for thought? I agree with Jim Palmer -- he created a superior EggCamper product -- after designing experimental aircraft...

BTW -- I'm not attempting to be argumentative simply sharing some important information for consideration by the group.

Originally Posted by redbarron55

Make sure what you use doesn't seal moisture IN.
The issues that have caused problems are mostly leaks from windows, refrigerators and plumbing inside and sitting and soaking into the floor.
Make sure that the top is sealed and the bottom will take care of itself as most water runs downhill.

[Hidalga]

Absolutely agree Bill.

Scamp has a serious design flaw with where their chassis/U-channel meets the flooring. When water runs down the fiberglass and gets in the U-channel trim (and either back flows to the inside or runs along the top of the chassis itself), the OSB flooring board ON THE EDGES acts like a dry sponge if butted up next to that U-channel.

Top and bottom coating are great, and water damage could easily be mistaken for leaking back/front windows, but how are you going to stop the penetration points on the edges of the board resting on the chassis against the U-channel?

I chiseled the flooring away from the U-channel a few inches that sat on the 4 contact points on the chassis, and then used a tube of Flex Seal to seal the snot into the edging. I also had to cut out a 4"x5" section of flooring right over the one of the chassis that clued me in to the initial water damage.

Scamp has plenty of serious design flaws. I know, because I've spent more money fixing the issues than on the initial trailer purchase. She's a constant project!

[floyd]

Rubberized undercoating sticks good to wood and metal.
It is cheap and comes in a rattle can.

[Bill Robison]

Hidalga --

Looks like you have enough first hand experience to chime in on this topic! I appreciate your supportive comments, although, perhaps it is not great news for any egg owners who want to protect all of their wood floor from potential deterioration over time. Especially Scamp owners - considering what you have shared!

With your experience - do you think coating the bottom area with Flex Seal or using your approach (explained above) are potential solutions? Or do you think it requires the dreaded task of lifting the egg from the frame - detaching & removing the entire floor - sealing new wood on ALL surfaces, sides and edges - then re-installing the entire floor and egg body? I think this is the real 'elephant in the room', which no one wants to mention out loud?

Do you have recommendations for the type of sealer? Resin only? Resin plus fiberglass cloth? How many coats, etc? This is a great place for some of the novices to learn about this important topic. Thanks!

Originally Posted by Hidalga

Absolutely agree Bill.

Scamp has a serious design flaw with where their chassis/U-channel meets the flooring. When water runs down the fiberglass and gets in the U-channel trim (and either back flows to the inside or runs along the top of the chassis itself), the OSB flooring board ON THE EDGES acts like a dry sponge if butted up next to that U-channel.

Top and bottom coating are great, and water damage could easily be mistaken for leaking back/front windows, but how are you going to stop the penetration points on the edges of the board resting on the chassis against the U-channel?

I chiseled the flooring away from the U-channel a few inches that sat on the 4 contact points on the chassis, and then used a tube of Flex Seal to seal the snot into the edging. I also had to cut out a 4"x5" section of flooring right over the one of the chassis that clued me in to the initial water damage.

Scamp has plenty of serious design flaws. I know, because I've spent more money fixing the issues than on the initial trailer purchase. She's a constant project!

[Hidalga]

Lost my explanation twice responding to this. Bottom line, uncoated floor EDGE contact with U-channel on chassis, BAD.
Big reason why Scamp has floor rot. Must add gap in flooring and waterproof these 4 flooring edge points. Doesn't matter how much the top and bottom are weatherproofed.