So how big of an issue is water damage?

[rbeemer]

It is usually not the sides of plwood that have problems but the ends. Make sure those get sealed really well

[48Rob]

of course I took maintenance and, necessary, repair into account when I made my statements. The additional goops and sealants that I spoke of was refering to something that might be done during assembly, at the factory, rather than re sealing as a part of general maintenance. We have a 1989 Layton fifth wheel, built as I described, with sticks and staples. It has held up well, but I do have to check things out periodically. I have had some water intrusion that I have had to address, but for being 23 years old and spending every day of it's life sitting outdoors, it's in fair shape. Additionally, as I stated, When, if ever, I get to my build, I will not be slapping it together as we did at Santa Fe. The cabinet maker in me will not allow it

Carl,

Sorry that I misunderstood.

I brought that up because it is so commonplace for someone to buy a new trailer and assume that "because it is new, it doesn't need anything" for a long time.

Same with a used trailer that has been renovated or repaired, especially by "a shop".
They're pro's, it should be good for a long long time...

The problem is though, that no matter how good a shop or factory, or individual builder is, the trailer doesn't have a lifespan of 20 years without annual attention to maintenance.
Properly cared for, 50-70 years is not unrealistic, no matter how high, or poor the quality of the original build.

Rob

[doug hodder]

What always amazes me is the makeshift repair that one might do on a leaker....IE...just blob on a wad of silicone on a seam rather than actually remove the trim piece or item and replace the original butyl tape or sealant. If it leaks...find the problem and take care of it correctly....a quickie/makeshift repair only puts off the repairs to come, and they will only grow. Doug

[angib]

Just "think like water" and try to shed it as you do your build.

Sounds like "DUH" advise but it does have merit.

I would add:

Never underestimate the perversity of water - you may think that water will flow from A to B to C, but there is nothing water likes as much as landing at A and then just sitting there - or indeed landing at C and flowing uphill to A.

The pleasure that water gets in confounding one's assumptions is, at best, sadistic.

[afreegreek]

it's not water getting in that's the problem.. it's water that can't get out.. I read topic after topic on this site and it's all about sealing this and sealing that... I'm sure if I did a word search on here for breathing or ventilation I'd come up empty..

it's the same with home construction.. you got a bunch of "envelope engineers" running around putting poly on the inside, house wrap on the outside, blue skin and caulking by the gallon around the windows.. cover the whole thing with vinyl siding.. then 15 years later they hire someone to come and fix all the rot... this is not the case with pre 'vapour barrier -house wrap' houses..

look, the reality is you are not going to seal anything... the best you'll ever get is sealished... make sure you build to let things breathe.. give things like wall cavities some air circulation, keep the windows open here and there and keep a 60 watt light on in the damp season.. don't wrap it up in a tight fitting tarp with all the doors and windows closed and no heat..

wood is a sponge and will absorb water to it's saturation point... there is nothing you are going to apply that will stop it either.. a water molecule is one of the tiniest thing there is and it will get through whatever you put on the wood.. so.. in the end your are not sealing water out, you are sealing it in.. saturation point in wood is a much higher moisture content than is needed for rot and decay.. if you don't get it dried out it will rot.. nature designed it that way..

what did nature design to dry things out? air movement

[doug hodder]

I think I'll still make the efforts to keep the water from getting in to begin with.

[aggie79]

it's not water getting in that's the problem.. it's water that can't get out.. I read topic after topic on this site and it's all about sealing this and sealing that... I'm sure if I did a word search on here for breathing or ventilation I'd come up empty..

http://www.mikenchell.com/forums/viewtopic.php?p=687686#687686

[Oldragbaggers]

I think I'll still make the efforts to keep the water from getting in to begin with.

I'm with you Doug.

[48Rob]

Mr. Greek,

I'll certainly go along with the thought that ventilating a trailer is good practice.
Allowing/planning for wood that may get wet to be able to dry naturally as quickly as possible is also wise.

However, to suggest that we are wasting our time even bothering to attempt to seal wood that may be wetted is a bit much.

I have a fair amount of experience repairing water damage to trailers and have found that often, if an area that had been damaged from wetting had been sealed with paint, varnish, or something that would inhibit or slow the water from soaking in, the leak could have been repaired and the stain touched up without requiring wood replacement.

While sealers won't protect the wood forever, or from any type of exposure, they can and do vastly extend the amount of time a trailer owner has between noticing a problem and correcting it before major damage is done.
Along with semi annual checks/inspections of the exterior seals, trailer lifespan is greatly increased by using "sealers".

In teardrops, or trailers constructed similarly, with 1 solid wall (sheet of plywood) and a painted or clad exterior, there is the danger of reverse vapor flow.
Though obviously not the same scenario as a stud wall cavity where one is trying to prevent vapor flow from traveling one direction, or the other, the same results can occur if the plywood is not completely sealed.

If one side, an edge, or portion thereof is left unsealed, vapor will attempt to flow from inside to outside, or vise-versa.
Since most trailers employ an impervious exterior skin, making the assumption that there is no need to "seal" the wood for good measure/extra protection just in case" is risky at best, since most water damage begins when the "impervious" outer layer is compromised.

In the end, the best case scenario would be to use raw natural wood and allow it to air dry as quickly as possible.
But, since this is impractical unless you live in a very dry climate, sealing the wood to aid shedding the water, and slowing and preventing penetration is the next best bet.

While it is possible that some people overdo the attempts to seal things, they are at least making an attempt to protect their investment.
If you can't get the wood to dry quickly, as you point out it will rot, but if you know that you may have wood that will get wet and can't dry, it would be foolish to just hope it will end well...without doing anything.

Rob

[afreegreek]

I'm not saying that sealing is a total waste of time.. what I am saying is sealing and ignoring the the need for proper ventilation is ignoring 9/10 ths of the problem..

you can seal a trailer so that no water from rain or road spray can penetrate and think you're done... what about the 1 litre per 24 hour period you are pumping in from your lungs.. where is that going? what about the moisture in the surrounding air (humidity)..?

I'm not here to write my doctoral dissertation on wood rot here, hence the one or two paragraph statements but I am trying to plant a seed in peoples minds to think a little beyond the obvious...

I am not a TD builder.. I'm a professional cabinetmaker and boat builder. I've been doing it for 30 years, 25 as a pro.. people hire me because when they build a 150 foot, 25 million dollar yacht they want to make sure the person doing the work knows a little bit about what they are doing.. if you want to hear what I'm saying that's fine.. if you don't, it's no skin off my butt.. it's your trailer..

here's a video of our latest launch in 2010.. http://www.youtube.com/watch?v=8VQDQE6e2F0

a good portion, about 25% of the woodwork you see is my work.. it's just one of 9 multimillion dollar yachts I've been a part of in my career.. I've also built a number of wooden kayaks, row boats, sail boats, and travel trailers for my own use.. one of which I'm living in now.. I build them, use them and then sell them.. not once has anyone come back complaining about wood rot or leakage.. perhaps I'm just lucky?

[afreegreek]

I think I'll still make the efforts to keep the water from getting in to begin with.

I'm with you Doug.

nothing wrong with keeping as much water out as possible but if that's all you're doing it isn't enough.. want some proof? take a piece of dry 2x4, place it in a zip-lock plastic bag and lay it out in the sun for a few months and see what happens to it.. the sun will evaporate the moisture in the wood and it will condense on the plastic.. what used to be a moisture content of say 14% evenly distributed in the wood will now be drops of liquid water on the plastic.. wherever those droplets absorb back into the the wood through contact with the plastic will be much higher MC than 14% in those localized areas.. if left long enough the decay process will start.. this is with no extra moisture that what was in the wood to begin with.. it's that simple..

want another? seal a piece of 2x4 with CPES or whatever you want and weigh it with an accurate scale.. put the piece in a bucket of water for a week or two, remove it, wipe it dry and weigh it again.. the difference in weight will be water absorbed through the sealant.. what this will show you is exactly what I stated, there is no such thing as sealed..

wood moves and movement (expansion and contraction) will cause micro fissures in epoxy and other rigid sealants.. not only will water vapour be absorbed through the sealant itself but will increase with age as those micro fissures grow.. especially after many freeze thaw cycles..

the point I'm trying to make is not that sealing is a waste of time because it is not.. the point is that sealing without making allowances for ventilation is not going to stop moisture absorption it is only going to slow it.. without some way for that moisture to escape the moisture content will increase to the level needed for it to decay..

wood has been used for thousands of years... long before epoxy and CPES were invented and there are many examples around to show that sealing out water with such products is not the only way to prevent wood decay.. in fact the Japanese buy raw logs and submerge them in deep lakes to prevent decay as water is only a portion of the natural decay process.. free oxygen atoms are also needed..

trees are full of water, the only portion of a tree that is alive is the cambium layer, all of the heart wood is essentially dead.. the reason trees can stand for a thousand years is because the moisture content is too low for it to decay.. in other words water is not the problem, it's the amount of water.. each species is different but in general a moisture content above 20% is what will start the decay process..

[48Rob]

if you want to hear what I'm saying that's fine.. if you don't, it's no skin off my butt.. it's your trailer..

Mr. Greek,

I've found a lot of the information you've posted on the board to be helpful, however, you may not be aware that often the delivery reeks of the same attitude displayed in the above quote, leaving people less focused on the information, and more so on the attitude.

I'm very interested in hearing what you are saying, and hope to learn.
I can't speak for others here, but when information is presented in a manner that doesn't make one feel that they're being talked down to, it is much easier to absorb.


Happy holidays!

Rob

[LDK]

Hey Robbie

If you want to get by cheap you could use polyurethane diluted with mineral spirits for several coats on your sidewalls and end grains and then maybe several coats full strength. On your trim and screw holes you might try OSI micro premium gutter sealer. Since you're skinning with aluminum that might be worth thinking about.

[Oldragbaggers]

I think maybe there is a gap in communication of information about sealing the trailers. I can't speak for everyone here but for myself I am talking about sealing the outside of my trailer to keep water from getting in. I am not, however, going to seal up my trailer in a plastic bag so I can just sweat the wood after it's built. I am going to travel in it. I am going to open the windows and turn on the fan. I am going to park it under the trees and let the breeze blow through it.

I lived on sailboats for 4 years. Have owned and sailed them for 30 years. Fiberglass sailboats. Waterproof from the outside (and for good reason) sailboats. The really good builders seem to go to a lot of trouble with sealants and such to assure that the water stays on the outside of the boat. Close them up tight and batten down the hatches and if things are working as they should you should be able to sail hard into the wind all day long with water washing over the deck and you should still find your cabin dry when it's done. But then you open your windows and hatches, you use your ventilating fans, you expose it to fresh air and sunshine on a regular basis and all is right with the world. You don't, however, consider not sealing it up and making it moisture tight because you're assuming the user won't have the good sense to open the windows and air it out regularly.

My observation is that this forum is populated with some pretty intelligent people with all kinds of experience to bring to the table.

[Robbie]

Hey Robbie

If you want to get by cheap you could use polyurethane diluted with mineral spirits for several coats on your sidewalls and end grains and then maybe several coats full strength.

LDK,

Would something like this work for the application you've described? I figure with a quart I can just brush it on over the end grains and a few inches into the field from the edges. This might be stupid but why do you need to dillute it? And should I still lay a few coats of primer over the entire outside once this stuff dries?

http://www.lowes.com/pd_45868-24-630004 ... facetInfo=

And I plan to use the same 3M marine sealant that Tom used when he skinned his trailer. I definitely will not skimp on that.

Thanks,
Robbie