Poplar for framing?

[Ned B]

I'm a long way from putting saw to wood, but thought I'd put this to the experts just the same.
My TV has a 3500 lb tow rating (well, call it 2500 to be safe after driver/passengers/gear). TO that end, I'm planning on about a 1500 lb goal for my eventual TTT (modified weekender) build. I've got a pretty well equipped woodshop (or will once I get it all in one place following my current move). I have a contractor saw, two bandsaws, planer, jointer, router, along with the 'usual' hand and smaller power tools (drill/drivers) etc...

I've got a Kreg Jig, and was thinking that a stick built sandwich for the framing (ply, wood frame & panelling) would be well within my skill sets. I've seen 'we all overbuild' in many of the threads I've been reading. To that end, I'm considering using 1x3 (or 1x2) poplar over 2x2 pine for framing. Poplar is the 'softest' hardwood, but is still strong enough that it is often used as a 'secondary' wood in fine furniture. Has anyone used Poplar in their build or am I barking up the wrong tree?

[aggie79]

For my insulated floor, I used, 1x2 poplar with 1/4" ply both sides:



This is a picture of the side view. (The MDF on top is a straight edge that I used to guide the angle cut to match the profile curve.)



The floor is plenty stout.

I used "plywood framing" for my insulated walls - 1/8" ply both sides - but poplar would be a good option too.

Take care,
Tom

[Ned B]

Tom,
thanks for the very quick reply. So in essence you built a torsion box with insulation in the 'voids'. Makes sense to me!

[dh]

I always thought Balsa was the softest hardwood. Anyway, no reason poplar wouldn't work. Some use poplar for the last spar where the hinge attaches.

[asianflava]

I framed with pine for cost reasons. I used poplar on the "studs" where the door and hatch hinge attached.

[Ned B]

I always thought Balsa was the softest hardwood. Anyway, no reason poplar wouldn't work. Some use poplar for the last spar where the hinge attaches.

OK, true... Balsa is softer. I suppose I should have added 'among readily available, and Useful species'... ie, vs Maple or Cherry...

[KenC]

I used pine for the walls and a combination of oak and poplar for the door frame and jamb

[bdosborn]

I've got one or two pieces of poplar in my framing:




Its worked out pretty good so far

Bruce

[planovet]

I framed with pine for cost reasons. I used poplar on the "studs" where the door and hatch hinge attached.

This is what I did also.

[bobhenry]

The southern yellow pine board is comprised of 4 species of pine.

Loblolly ~ long leaf ~ short leaf ~ and slash

If you look at this strength chart you will see the reason that all my structural members such as spars and floor framing was cut from #1 grade SYP 2 x 12's

When you compare it to the poplar listed last in the hardwood section you can easily see the difference.

http://www.woodworkweb.com/woodwork-topics/wood/146-wood-strengths.html

[aggie79]

Lots of good points brought up so far.

Pine is plenty strong for walls/floors for your frame. I chose Poplar over pine because of the constuction method you described. Using pocket screws, there isn't much wood to "bite" into. My thought was that poplar gives better screw-holding capacity. Of course, once your first plywood skin is attached, then it doesn't matter how you put together your frame.

As Bob Henry says, if you can cut/mill your own 1x2s from #1 SYP 2x stock, then that would be most cost effective route to go.

[Micro469]

I really have to reply to this thread. I also used poplar in my build. I used it for framing and also on the outside as the molding.
That said.. I WOULD NOT RECOMMEND POPLAR IN ANY PLACE WHERE IT MAY COME IN CONTACT WITH MOISTURE!!!!

Any poplar I used that got wet turned black and very soft. I have some pieces that I can dig into with my fingernail and pull chunks of sawdust out. Even when painted, I have black spots coming through the paint. My front box is going to have to be remade because of the rot in the poplar.

Would I use it again?? NO! Next time I'll use spruce or fir or even pine.
Poplar rots too fast.

[Lgboro]

Pine was way too heavy for me -- I have a half built tear of pine that was too heavy and I just quit working on it and restarted on a new one. My current build is all cedar with 1/8 inch cedar strip inside and will have aluminum skin over the framing and insulation. Biscuit joints and dowel pin construction exclusively without any screws so far. Haven't mounted to my trailer yet but the weight is much lower this time (overbuilt I'm sure but with much lighter materials).

[caseydog]

I used birch plywood, and poplar lumber for my entire build. There is not a single piece of pine.

I like poplar, and I like birch plywood. So, that's what I used.

It has been reasonably stabile -- nothing has warped in my build. I've camped in all seasons, and gone from desert climate to the beach.

Just trying to buy a straight piece of pine is a challenge, and then you better use it right away, or it will turn into a pretzel.

BTW, my 4X8 weighs about 600 pounds.

CD

[caseydog]

I really have to reply to this thread. I also used poplar in my build. I used it for framing and also on the outside as the molding.
That said.. I WOULD NOT RECOMMEND POPLAR IN ANY PLACE WHERE IT MAY COME IN CONTACT WITH MOISTURE!!!!

Any poplar I used that got wet turned black and very soft. I have some pieces that I can dig into with my fingernail and pull chunks of sawdust out. Even when painted, I have black spots coming through the paint. My front box is going to have to be remade because of the rot in the poplar.

Would I use it again?? NO! Next time I'll use spruce or fir or even pine.
Poplar rots too fast.

I don't think that poplar is an exterior grade wood. I didn't use it anywhere on the outside of my TD -- for some reason, I knew it shouldn't be used on the outside of anything. I don't recall if I read that somewhere, or learned it the hard way.

CD