Argosy motorhome floor replacement

[bkahler]

As the title states I'm getting ready to replace the wood flooring in my 20' Argosy MH.

Trailers floors are fastened different than the motorhome floors (which is why I'm posting here instead of the general repair forum). At least that's what I've noticed from reading the forums and also from experience owning 3 different Airstream motor homes and a 31' Excella trailer.

I have found that the floor in my 74 Argosy mh is fastened different than the 86 345 that I dismantled. In fact there is a huge difference in construction. The Argosy appears to just have a few fasteners located in the seams between plywood sheets with NO fasteners anywhere else. The 345 had large screws on on each frame member AND a large number of nails as well. The important difference here is the Argosy floor was basically a floating floor where the 345 floor was fastened such that no movement was allowed what so ever.

I'm working on the assumption that most design changes are geared toward providing a better product and if a cost savings is realized so much the better. In this case more screws and adding nails as well would have cost more. So with that in mind I'm planning on using a generous amount of fasteners to hold the wood floor down.

Any suggestions on which fasteners to use? If I remember correctly the 345 used Phillips head style self tapping screws. Anyone know of a source for that style of screw?

Also on the subject of plywood flooring. Any thoughts on coating both sides of the plywood with Spar varnish? Right now I'm leaning towards applying Spar varnish but I'm not 100% sure it will be worth the extra effort.

Any thoughts?

Brad

[92landyacht]

Not directly related, but on my 92 LY they used glue to hold the floor down and only used bolts along the perimeter. Of course the construction of the floor may be very differant since in 92 they used 1.5" high density foam insulation between the wood and the metal under-belly pan. No fasteners of any kind were used in the center area.

See my post here on my floor repair:
92 Land Yacht Project Continues

[Phrunes]

Originally Posted by bkahler

As the title states I'm getting ready to replace the wood flooring in my 20' Argosy MH.

Trailers floors are fastened different than the motorhome floors (which is why I'm posting here instead of the general repair forum). At least that's what I've noticed from reading the forums and also from experience owning 3 different Airstream motor homes and a 31' Excella trailer.

I have found that the floor in my 74 Argosy mh is fastened different than the 86 345 that I dismantled. In fact there is a huge difference in construction. The Argosy appears to just have a few fasteners located in the seams between plywood sheets with NO fasteners anywhere else. The 345 had large screws on on each frame member AND a large number of nails as well. The important difference here is the Argosy floor was basically a floating floor where the 345 floor was fastened such that no movement was allowed what so ever.

I'm working on the assumption that most design changes are geared toward providing a better product and if a cost savings is realized so much the better. In this case more screws and adding nails as well would have cost more. So with that in mind I'm planning on using a generous amount of fasteners to hold the wood floor down.

Any suggestions on which fasteners to use? If I remember correctly the 345 used Phillips head style self tapping screws. Anyone know of a source for that style of screw?

Also on the subject of plywood flooring. Any thoughts on coating both sides of the plywood with Spar varnish? Right now I'm leaning towards applying Spar varnish but I'm not 100% sure it will be worth the extra effort.

Any thoughts?

Brad

I really like spar...but it may offgas more than you want in those tight confines.

[dadstoy]

Brad,

Not that I have any appropriate advice for you, but those are the screws I used when I replaced a few sections of my floor. There is a special name for those screws but I don't remember it!

Those are the screw that the plywood flooring is secured with on my 20' enclosed car hauler (my ATV trailer). They are available at Home Depot. I had gotten a box because some on the trailer had broken due to flexing.

You can not rely on the self tapping on those to go through the sub frame...I tried. I also broke three drill bits in making pilot holes for the screws...not sure what that was all about.

I painted the edge and top of my plywood sections with Kilz (spelling?). I'm glad I did because I still have water leaking at the fresh water filler...that one pisses me off...another AS crappy design.

Good luck and thanks again for diagram on the AS floor/wall construction.

[Phrunes]

Elevator bolts?

[bkahler]

Originally Posted by Phrunes

I really like spar...but it may offgas more than you want in those tight confines.

How long do you think the off gasing would last, days, weeks, months, years...?

It's going to be months before the interior is built inside once the floors are replaced as I have plenty of other work to do outside in the mean time. I want to leave it open so I can watch for leaks until I know I have them all.

I was working on part of the cockpit floor this evening and a nice strong thunderstorm blew through. I found another leak that I didn't know about

Brad

[bkahler]

Originally Posted by Phrunes

Elevator bolts?

The problem with elevator bolts is it is a bolt and nut situation. The bottom shell of an Argosy (and 345, 310, ect) motorhome is made of of 1"x2" steel tubing welded together in a grid fashion. The Argosy and the Classic series both have the steel grid, the difference is in how Airstream constructed the floor on top. There is only marginal access from below to fasten the nuts in place.

On the Argosy (at least in 1974) there was an aluminum sheet placed under the grid, the grid spaces were filled with white 1" styrofoam and the wood was laid on top of the grid and then a few fasteners were set between the seams of the plywood. It was more of a floating floor arranagment.

On the 86 310 that I dismantled it had the same steel tubing grid but the difference was Airstream laid a sheet of thin galvanized steel on top of the grid and then laid the one piece OSB sheet on top and then nailed and screwed it to the tubing grid. I'm guessing this arrangement provided for a much more rigid structure.

One other point is the 345 doesn't have an insulated floor whereas the Argosy does. Yay Argosy...

Brad

[bkahler]

Originally Posted by 92landyacht

Not directly related, but on my 92 LY they used glue to hold the floor down and only used bolts along the perimeter. Of course the construction of the floor may be very differant since in 92 they used 1.5" high density foam insulation between the wood and the metal under-belly pan. No fasteners of any kind were used in the center area.

See my post here on my floor repair:
92 Land Yacht Project Continues

Was the vapor barrior part of the original installation?

Interesting, it's almost as if Airstream went back to how the Argosy floor was constructed sans glue in the Argosy. Your floor is definitely better insulated as well. It must be really tough to make a motorhome water tight. Seems like they all leak.

Thanks for the info!

Brad

[bkahler]

Originally Posted by dadstoy

Brad,

Not that I have any appropriate advice for you, but those are the screws I used when I replaced a few sections of my floor. There is a special name for those screws but I don't remember it!

Did your coach have any nails in the floor along with the screws? I had to burn the heads off of every nail and screw on the 345 floor to get the decking removed. Pain in the back side!

Those are the screw that the plywood flooring is secured with on my 20' enclosed car hauler (my ATV trailer). They are available at Home Depot. I had gotten a box because some on the trailer had broken due to flexing.

Thanks for the tip. The closest for me is Lowes so I'll check them out tomorrow.

You can not rely on the self tapping on those to go through the sub frame...I tried. I also broke three drill bits in making pilot holes for the screws...not sure what that was all about.

I kinda figured pre-drilling would be the way to go. I've broken a few drill bits on the Argosy already as well

I painted the edge and top of my plywood sections with Kilz (spelling?). I'm glad I did because I still have water leaking at the fresh water filler...that one pisses me off...another AS crappy design.

You got the spelling right I need to check to see if Kilz is water proof. If off gasing does turn into an issue with Spar varnish then Kilz might be the answer.

It would surprise me if Spar varnish does have bad off gasing problems, after all isn't it used in boats?!

Good luck and thanks again for diagram on the AS floor/wall construction.

Glad to help!

Brad

[Phrunes]

I originally replaced my Argosy trailer bulkheads with panels finished with spar. I cured them in the sun for a week before they stopped gassing. My subfloor is coated with Kilz, about the same time to offgas but the kilz was inside the trailer out of the sun. So, I'm not sure which one would actually cure faster. The spar definitely offers more water repellence, but it will rub off against the framerails if there is movement. I added sand to my kilz for a texture for the floating floor to grip to.

[bkahler]

Originally Posted by Phrunes

I originally replaced my Argosy trailer bulkheads with panels finished with spar. I cured them in the sun for a week before they stopped gassing. My subfloor is coated with Kilz, about the same time to offgas but the kilz was inside the trailer out of the sun. So, I'm not sure which one would actually cure faster. The spar definitely offers more water repellence, but it will rub off against the framerails if there is movement. I added sand to my kilz for a texture for the floating floor to grip to.

Since I will be putting the flooring in place long before the coach will ever be used to camp in the off gassing sounds like it won't be a problem for me.

Thanks for the info!

Brad

[Phrunes]

You're welcome. I would worry more about any shifting rubbing/flaking off the spar and diminishing its water repellency. Have you considered using a rubberized roof coating?

[Smartstream]

Brad talk to a truck body outfit. I built a flat bed many years ago and used Apitong which is the wood commonly used in truck and trailer beds. The Apitong supplier had some self tapping screws that they used. They were 1/4" or 5/16" and had a thorx drive flathead and were very tuff.

[bkahler]

Originally Posted by Smartstream

Brad talk to a truck body outfit. I built a flat bed many years ago and used Apitong which is the wood commonly used in truck and trailer beds. The Apitong supplier had some self tapping screws that they used. They were 1/4" or 5/16" and had a thorx drive flathead and were very tuff.

Dan, thanks for the info. Yesterday morning I stopped by Lowes and they had a product called TEKS (probably similar to what Dean was suggesting). They are self tapping with a couple of ears just above the drill bit portion that bores the wood hole slightly larger and then they break off as soon as they contact metal. Kinda neat to watch them work. Anyway I used them on the strip of flooring in the cockpit and they worked very well.

I'll try and post a picture of the screws later today so you can see what I'm talking about.

Brad

[crabbey1]

I am using these screws in my floor replacement of a 1976 Argosy 22'. They seem to be working great so far. I just pre drill the holes with this bit and then allow the screws to self tap the frame... Good luck!

[bkahler]

Crabbie,

Those are the same screws I'm using. I believe they are called TEKs.

They definitely are easy to use.

Brad

[crabbey1]

Sure are! I love them. I just hope they are as strong as the original E-Bolts when I double up on the amount. 2 screws per E Bolt...