Teardrops n Tiny Travel Trailersor t n ttt for short (tnttt.com) |
Ambitious Goals
24 posts
• Page 2 of 2 • 1, 2
Re: Ambitious Goals
by scotta » Fri Jun 08, 2012 11:04 pm
Spent the month of June, 2010 in a 4x8.Didn't need galley. Wasn't wide enough. Spent June 2011 in a 5x7. No galley, plenty long enough. Make sure to have a good fan in western US. Congrats on your masters, good luck on doctorate. Got my degrees from State. Live in northeast Mississippi,Elvis has left the building , but I'm still here
- scotta
- Teardrop Inspector
- Posts: 21
- Joined: Mon Oct 05, 2009 10:32 pm
- Location: mississippi
Re: Ambitious Goals
by mezmo » Sat Jun 09, 2012 1:56 am
Hi jonwwo,
First off, welcome to this forum full of friendly informative people.
I'd go for your first proposal. I'd also recommend a 5wide, that's a big
point of debate for some, but my impression after absorbing all the pros
and cons of it, is that the extra width is worth it. One proven low tech
way to decide for yourself is to use a couple/three sheets of cardboard
or thin ply to mock up the volume [4ftx4ftx8ft(+/-) or 5ftx4-5ftx8ft(+/-) -
what ever size/volume you want to check out], then decide what will work.
Also, I'd consider 2 doors as a necessity, especially for two people using
the TD, but also for the ease of use of the TD in general. Framing for and
installing a door isn't that much more work/effort than doing the same for
a window. And 2 doors are safer than 1, period. And Roly's recommendation
for including a roof vent is also spot on, although I'd recommend making a
curb around the vent opening on the roof [3/4-1&1/2in high] and then
mounting the roof vent on that. That'll help stop rain deluges from overwhelming
the vent's built in curb height - just one of my idiosyncracies.
I'll state the obvious now, and say to remember that the nominal wood
sizes aren't their real sizes [1x2 is really 3/4x1&1/2 etc.]. I only say that
to reinforce the necessity to make sure all of the materials are of the same
dimensions when necessary. E.G. A 1/16th or even a 1/32nd, let alone a 1/8th
inch difference in the wood thickness used for the framing and the thickness
of the foam used can drive you nuts. Also just be aware that some of the
nominal plywood sizes in the big home centers isn't always what the advertised
dimensions are. Just ensure it IS 4ft x 8ft, and it really IS 1/8 or 1/4 or 3/8
or 1/2 or 5/8 or 3/4 in thick. 23/32 is not 3/4, and so on for the other
dimensions. A lot of the plywood is now in these "off" dimensions. And there
is also some plywood that is dimensioned in metric sizes now. Be sure to
look up their inch equivalents if you have to use those.
The reason I prefer your first proposal is that you are basically proposing using
a small scale SIP, and with them, a "thick" one is much stronger than a "thinner"
one. For a TD, the weight addition of using thicker foam is negligible. Just be sure
to include hard points, the same thickness as the foam, situated within the foam
field of the SIP panel where you need them for attachments and such.The main
practical thing to remember is to choose a thickness that'll work with any purchased
door's or window's wall thickness requirements, if you use them. If you build your
own doors/windows then it's not that much of a consideration as you'd build them
to fit the wall thickness you use/choose.
For ease of joining and building the panels I'd suggest using perimeter framing
around the outside perimeter of the panels and perimeter framing around any
openings within the panels too. You need something to attach the doors and windows
to and foam itself wont work as it cannot "hold" screws. Since you are wanting a simpler
[and hopefully faster] construction method, gluing and wood screwing the panels
together where they meet at their edges is easy to do as you'd be gluing and screwing
wood to wood and through wood and into wood. 3/4in thick perimeter framing would
probably be fine and a bit cheaper [but not that much overall really] but I'd go with
1&1/2x1&1/2in framing, mainly for the added area it gives for connecting the
panels together and attaching the items [doors, windows, shelves, lights etc.] that
you need to attach to the panels themselves. It's a lot easier and less frustrating to
hit a 1&1/2in wide area than it is a 3/4in wide area when screwing and it gives more
surface area for gluing. I don't think the cost or weight difference between 3/4 and
1&1/2in perimeter framing is that much but you need to decide what is best for you.
Here, the thicker wall would be stronger and easier to build I think - but that is just my view.
Since your design doesn't strictly use a 'torsion box' as a base [the bottom/floor] I
think your first design works the best. [you can make the floor a SIP and thus a 'torsion box'
if you use perimeter framing on it. You can still have the bottom plywood sized to go
under the wall thickness to that's outer skin when making the floor a SIP.] You do end
up with the whole body being a larger torsion box once all the panels [floor.side,ends,roof]
are screwed/glued together.
Your first take on attaching the floor and walls to the frame is much stronger and
safer in my view. The wall sits on the frame and is attached to it and is supported by it.
On your second take, the wall only sits on and is only supported by whatever number of side bolts
you use. I like the redundancy of the continuous support of your first design. It wouldn't
be as affected by road vibrations as much either as your second design. I'd also go with
the floor of your first design for the reasons that; it'd be stronger, and help avoid
condensation problems that'd occur with the water vapor that the mattress absorbs from
the sleepers hitting a cold floor surface. I'd also get a continuous sheet of cheap
vinyl flooring to top the floor with before you put the mattress down - again to stop
any water vapor from reaching the plywood in the floor. [Don't forget it'd be easy to make
the floor a SIP with a perimeter frame.] Plain single thickness plywood floors are used
but their success depends on the climate I think. You're in a HUMID climate now, going
to a lesser but still humid climate. I think it'd be worth it.
I'm running out of steam here so I'll just mention a few things in closing. Check out the
Foamie section for a lot of ideas/techniques that may be helpfull for you. Forum member
Linuxmanxxx [also in the manufaturers section] there, recommends 3M 30NF fastbond
contact cement [light green in color for ease of application] for gluing foam and plywood
etc.. It's water based and low/no odor. Most use Titebond II for wood to wood but there
are other glues available too. An old-time wooden boat water-proofing method has
been revived there for use as an exterior skin. It's done by coating the TD/TTT body in
waterproof glue [Titebond II] and then embedding canvas in that [techniques are in the
section and elsewhere] and then recoating that with another coating/layer of the full
strength glue or somewhat diluted glue. Then paint it with a couple coats of a good UV-proof/
resistant paint [enamel probably best]. This is needed to protect the non-UV resistant canvas
and glue skin. There are several examples of this done there and even a couple in the Build
Journal section. It is a best practice to radius all the outside edges of the assembled TD/TTT
body before you cover with the glue and canvas/fabric If you can as it makes wrapping the
canvas/fabric skin over the edges much easier and smoother. A 1/2-3/4 in round-over bit
in a router would do it fine for you. [A router is a very handy tool in general for a build if you
have one or can get one.] If you don't have a rear hatch then you will simplify building immensely.
And it is a good idea to include full-width shelves or bulkheads or storage cabinet walls if they
go with your needs/design. Since these are usually mounted perpendicularly to the other
panels they impart a great amount of rigidity to the TD/TTT body by the triangulation
they inherently impart. And finally, -it should have been mentioned earlier- a flat panel design
will be easier and faster to build compared to those designs with curves. Curves impart strength
but they also impart complexity and additional build-time. The mini-SIP approach helps with
the strength part and flat panels avoid the complexity. Profile interest - over a true box shape -
can be achieved by angling the front and rear panels in a fashion agreeable to you. One of the
simplest I've seen is to just pick a point [mid-point works well] on the front and rear walls and
extend the sidewall length there a few inches out from the vertical and divide and make the
front and rear into two panels so there is a 'top' and 'bottom' panel that meet at that projected
mid/point and the roof panel and the floor panel respectively. Obviously the side-walls then
need to be shaped to match but with flat panels that is not difficult.
'Hope this info is beneficial and have fun designing and building.
Cheers,
Norm/mezmo
First off, welcome to this forum full of friendly informative people.
I'd go for your first proposal. I'd also recommend a 5wide, that's a big
point of debate for some, but my impression after absorbing all the pros
and cons of it, is that the extra width is worth it. One proven low tech
way to decide for yourself is to use a couple/three sheets of cardboard
or thin ply to mock up the volume [4ftx4ftx8ft(+/-) or 5ftx4-5ftx8ft(+/-) -
what ever size/volume you want to check out], then decide what will work.
Also, I'd consider 2 doors as a necessity, especially for two people using
the TD, but also for the ease of use of the TD in general. Framing for and
installing a door isn't that much more work/effort than doing the same for
a window. And 2 doors are safer than 1, period. And Roly's recommendation
for including a roof vent is also spot on, although I'd recommend making a
curb around the vent opening on the roof [3/4-1&1/2in high] and then
mounting the roof vent on that. That'll help stop rain deluges from overwhelming
the vent's built in curb height - just one of my idiosyncracies.
I'll state the obvious now, and say to remember that the nominal wood
sizes aren't their real sizes [1x2 is really 3/4x1&1/2 etc.]. I only say that
to reinforce the necessity to make sure all of the materials are of the same
dimensions when necessary. E.G. A 1/16th or even a 1/32nd, let alone a 1/8th
inch difference in the wood thickness used for the framing and the thickness
of the foam used can drive you nuts. Also just be aware that some of the
nominal plywood sizes in the big home centers isn't always what the advertised
dimensions are. Just ensure it IS 4ft x 8ft, and it really IS 1/8 or 1/4 or 3/8
or 1/2 or 5/8 or 3/4 in thick. 23/32 is not 3/4, and so on for the other
dimensions. A lot of the plywood is now in these "off" dimensions. And there
is also some plywood that is dimensioned in metric sizes now. Be sure to
look up their inch equivalents if you have to use those.
The reason I prefer your first proposal is that you are basically proposing using
a small scale SIP, and with them, a "thick" one is much stronger than a "thinner"
one. For a TD, the weight addition of using thicker foam is negligible. Just be sure
to include hard points, the same thickness as the foam, situated within the foam
field of the SIP panel where you need them for attachments and such.The main
practical thing to remember is to choose a thickness that'll work with any purchased
door's or window's wall thickness requirements, if you use them. If you build your
own doors/windows then it's not that much of a consideration as you'd build them
to fit the wall thickness you use/choose.
For ease of joining and building the panels I'd suggest using perimeter framing
around the outside perimeter of the panels and perimeter framing around any
openings within the panels too. You need something to attach the doors and windows
to and foam itself wont work as it cannot "hold" screws. Since you are wanting a simpler
[and hopefully faster] construction method, gluing and wood screwing the panels
together where they meet at their edges is easy to do as you'd be gluing and screwing
wood to wood and through wood and into wood. 3/4in thick perimeter framing would
probably be fine and a bit cheaper [but not that much overall really] but I'd go with
1&1/2x1&1/2in framing, mainly for the added area it gives for connecting the
panels together and attaching the items [doors, windows, shelves, lights etc.] that
you need to attach to the panels themselves. It's a lot easier and less frustrating to
hit a 1&1/2in wide area than it is a 3/4in wide area when screwing and it gives more
surface area for gluing. I don't think the cost or weight difference between 3/4 and
1&1/2in perimeter framing is that much but you need to decide what is best for you.
Here, the thicker wall would be stronger and easier to build I think - but that is just my view.
Since your design doesn't strictly use a 'torsion box' as a base [the bottom/floor] I
think your first design works the best. [you can make the floor a SIP and thus a 'torsion box'
if you use perimeter framing on it. You can still have the bottom plywood sized to go
under the wall thickness to that's outer skin when making the floor a SIP.] You do end
up with the whole body being a larger torsion box once all the panels [floor.side,ends,roof]
are screwed/glued together.
Your first take on attaching the floor and walls to the frame is much stronger and
safer in my view. The wall sits on the frame and is attached to it and is supported by it.
On your second take, the wall only sits on and is only supported by whatever number of side bolts
you use. I like the redundancy of the continuous support of your first design. It wouldn't
be as affected by road vibrations as much either as your second design. I'd also go with
the floor of your first design for the reasons that; it'd be stronger, and help avoid
condensation problems that'd occur with the water vapor that the mattress absorbs from
the sleepers hitting a cold floor surface. I'd also get a continuous sheet of cheap
vinyl flooring to top the floor with before you put the mattress down - again to stop
any water vapor from reaching the plywood in the floor. [Don't forget it'd be easy to make
the floor a SIP with a perimeter frame.] Plain single thickness plywood floors are used
but their success depends on the climate I think. You're in a HUMID climate now, going
to a lesser but still humid climate. I think it'd be worth it.
I'm running out of steam here so I'll just mention a few things in closing. Check out the
Foamie section for a lot of ideas/techniques that may be helpfull for you. Forum member
Linuxmanxxx [also in the manufaturers section] there, recommends 3M 30NF fastbond
contact cement [light green in color for ease of application] for gluing foam and plywood
etc.. It's water based and low/no odor. Most use Titebond II for wood to wood but there
are other glues available too. An old-time wooden boat water-proofing method has
been revived there for use as an exterior skin. It's done by coating the TD/TTT body in
waterproof glue [Titebond II] and then embedding canvas in that [techniques are in the
section and elsewhere] and then recoating that with another coating/layer of the full
strength glue or somewhat diluted glue. Then paint it with a couple coats of a good UV-proof/
resistant paint [enamel probably best]. This is needed to protect the non-UV resistant canvas
and glue skin. There are several examples of this done there and even a couple in the Build
Journal section. It is a best practice to radius all the outside edges of the assembled TD/TTT
body before you cover with the glue and canvas/fabric If you can as it makes wrapping the
canvas/fabric skin over the edges much easier and smoother. A 1/2-3/4 in round-over bit
in a router would do it fine for you. [A router is a very handy tool in general for a build if you
have one or can get one.] If you don't have a rear hatch then you will simplify building immensely.
And it is a good idea to include full-width shelves or bulkheads or storage cabinet walls if they
go with your needs/design. Since these are usually mounted perpendicularly to the other
panels they impart a great amount of rigidity to the TD/TTT body by the triangulation
they inherently impart. And finally, -it should have been mentioned earlier- a flat panel design
will be easier and faster to build compared to those designs with curves. Curves impart strength
but they also impart complexity and additional build-time. The mini-SIP approach helps with
the strength part and flat panels avoid the complexity. Profile interest - over a true box shape -
can be achieved by angling the front and rear panels in a fashion agreeable to you. One of the
simplest I've seen is to just pick a point [mid-point works well] on the front and rear walls and
extend the sidewall length there a few inches out from the vertical and divide and make the
front and rear into two panels so there is a 'top' and 'bottom' panel that meet at that projected
mid/point and the roof panel and the floor panel respectively. Obviously the side-walls then
need to be shaped to match but with flat panels that is not difficult.
'Hope this info is beneficial and have fun designing and building.
Cheers,
Norm/mezmo
If you have a house - you have a hobby.
-
mezmo - 1000 Club
- Posts: 1817
- Images: 194
- Joined: Fri Jan 01, 2010 4:11 am
- Location: Columbia, SC
