bow shed lumber snapping -- too thick?

[Desert Sailor]

The strapping lumber I brought back from the sawmill (yes, we have a few in New Mexico) measures a real 1" x 4". According to David Stimpson's build manual, you build the form for the bows while building the first bow. This is very green, wet stuff. After snapping 2-13' pieces, I was able to get the first piece bent into place. So far I have snapped 3 more trying to get the 2nd piece in place.

Could the 1" material be too thick? Would I be better off planing it down to 3/4" (which is what I would be working with if I had bought the stuff from the local lumberyard)?
--
Mark

[Jim Ledger]

There will be a world of difference between the bendability of 3/4 and 1" stock. One inch is really overkill in this situation, especially if you don't anticipate a heavy snow load.

If you rout a small radius on the outside edges it sometimes helps keep splits from starting. It's also easier on the plastic.

[chas]

Planing to 3/4" could be 3-4 passes thru the planer. I'd split it to two pieces 7/16 x 4 with two passes in the table saw and tack them back together over your form. / Jim

[Desert Sailor]

This is pretty low-quality stuff. Ripping on the table saw to thickness would be much quicker if it were straighter. Unfortunately, it's wet and goes in many directions.

A few passes through the planer would be manageable. Never thought of routing out a radius on the outside edges. Worth a try. Not anticipating heavy snow loads here in Albuquerque, but our spring winds can be impressive.

[Ron Williamson]

If it's really that wet,it likely won't plane well either.
Rubbing paraffin wax on the planer bed will help.
R

[Mrleft8]

Yes.

[Ian McColgin]

If it's going to be a pain in the saw or planer, why not invest in some duct tape and styrofoam to make a cheapie steam box? Could be kind of fun.

[Desert Sailor]

If it's going to be a pain in the saw or planer, why not invest in some duct tape and styrofoam to make a cheapie steam box? Could be kind of fun.

Thought about building a steam box. It would certainly slow down the process, but it would certainly be interesting. There are enough "someday/maybe" projects in that file that would require the ability to steam bend wood. Not sure what kind of styrofoam you're talking about, but I think I'd head to the local big box for some large diameter plastic pipe. Might as well make one that will be around for a little while. The real challenge would be finding and cobbing together the burner/boiler half of the equation.

It would be a pretty big box -- the bows are 13' long.

If I did have to steam this stuff, how long in the box (once the steam gets going)? About an hour, give or take?

Bottom line -- if the planer doesn't work out, I'll be building the steam box...
--
Mark

[scottmacc]

If it's going to be a pain in the saw or planer, why not invest in some duct tape and styrofoam to make a cheapie steam box? Could be kind of fun.

I like that idea....moving out of my rented shop this weekend and will be building a Stimson shed over the boat once moved{20'x 40'}. am planning to rip down 20' 2x6's. I'm concerned about snapping them so will research a steam box.

[Desert Sailor]

Update -- planing down to 3/4" helps a little, but still snapping 'em off. Time to build the steam box, methinks.

But this is pretty junky wood. I can cut the 13' out of the 16' such that there are no knots in the center, but there is funky compression wood all over the place. Am I going to steam bend these into place, only to have the bows snap when they dry out?

[Desert Sailor]

UPDATE

Planing down to 3/4" helped, but I still snapped a few more. I really didn't want to invest a lot of time and $ in a steam box (I'm under some time pressure here). So I planed them down, cut out the 14' I need, wrapped a towel around the center section and soaked it with boiling water, letting it sit for 10-15 minutes.

So far, so good.

[MN Dave]

Cross grain?

[Mrleft8]

Cross grain?

No.... But it's not exactly happy either.....

[Desert Sailor]

No.... But it's not exactly happy either.....

I should take pictures of this stuff. "Cross grain" doesn't begin to describe it. I'm convinced that some of the sticks have grain that does a U-turn at the point of max bend...

[Mrleft8]

Remember that just because it doesn't snap when you're bending it, doesn't mean it won't snap later on, while under load.
You live in a dry climate which might make the lumber more brittle when dry than in other climates.
Have you looked into seeing if someone has a stand of bamboo near you?.... I'm on my way right now to take a guy to harvest 40 pieces of bamboo from my father's yard that he plans to use for pretty much exactly what you are trying to do.

[HarryH]

I've built two of the Simpson sheds, and here's my $.02. Simply put, paying a few bucks for fairly clear 1x3 strapping IS the least expensive approach. Even then, the occasional snapped bow will need to be relegated to shorter lengths for bracing etc. Picking over 1x3 bundles (not necessarily individual pieces, but good if you can) should give a small percentage of breakage.

On my second shed I tried to incorporate some re-sawn funky, knotty spruce ledger board. False economy for sure. Some bows came out a bit twisted, making assembly a pain at times....Most snapped at even modest knots, or kinked without snapping, requiring doubling up or patching. I finally gave up and went to the lumber yard and bought decent strapping. Unless you've got a bunch or time, patience and energy, and cannot afford strapping, I cannot imagine that you would want to spend time steaming and wrassling with nasty stock....as said earlier, it may cause trouble even if you do get it to shape without snapping in the process.

[SamSam]

In addition to being very green, wet, low quality, cross grained stuff, what kind of wood is it? Some bend easier than others.

[knottyBuoyz]

I used big box lumber store 1X3 spruce strapping. They allowed me to pick through the bundles to get the best pieces I could. If I remember correctly I only broke two pieces before I started soaking them down with the garden hose a half hour before bending. A bit short of steaming them but it seemed to work for me.

[Desert Sailor]

I've built two of the Simpson sheds, and here's my $.02. Simply put, paying a few bucks for fairly clear 1x3 strapping IS the least expensive approach. Picking over 1x3 bundles (not necessarily individual pieces, but good if you can) should give a small percentage of breakage.

Here in Albuquerque, there is (as far as I know) only one yard that sells strapping. It's not readily available at the the big box retail stores/yards. At this yard that caters to the trade, you won't be picking through the pile. You tell 'em how many pieces you want, they pull 'em and bundle 'em. You pay, load, and leave -- and maybe pray you got some decent sticks in there.

On my second shed I tried to incorporate some re-sawn funky, knotty spruce ledger board. False economy for sure. Some bows came out a bit twisted, making assembly a pain at times....Most snapped at even modest knots, or kinked without snapping, requiring doubling up or patching. I finally gave up and went to the lumber yard and bought decent strapping. Unless you've got a bunch or time, patience and energy, and cannot afford strapping, I cannot imagine that you would want to spend time steaming and wrassling with nasty stock....as said earlier, it may cause trouble even if you do get it to shape without snapping in the process.

If you live in a place where lumber is plentiful, then buying decent stock from the get-go makes perfect sense. Lumber out here is ridiculously expensive. That pro yard can sell strapping lumber all day long at $4.75 per 1"x3"x14' -- to film production companies (that New Mexico has spent major taxpayer dollars to attract) for set construction. At that price, alternative designs start to make sense. I don't enjoy having to soak every board (it's the time I begrudge more than anything), but I have to work with what I have.

[Desert Sailor]

In addition to being very green, wet, low quality, cross grained stuff, what kind of wood is it? Some bend easier than others.

Most likely Western White Pine. The trees for this lumber are harvested out of National Forests as part of fire prevention plans, and in an attempt to mitigate the damage to forests caused by bark beetles. Not the greatest stuff, but if I can bend it, it should serve well enough.

[Desert Sailor]

I used big box lumber store 1X3 spruce strapping. They allowed me to pick through the bundles to get the best pieces I could. If I remember correctly I only broke two pieces before I started soaking them down with the garden hose a half hour before bending. A bit short of steaming them but it seemed to work for me.

Lucky you. Can't do that here. Big boxes don't carry it, and the pro yard won't let you past the front desk.

Nice pics. Got one of the finished product?

[Mrleft8]

Sounds like there's an opportunity for an enterprising young person to open a proper lumber yard.....
It amazes me what people from other parts of the country have to put up with when it comes to buying lumber...

[knottyBuoyz]

Nice pics. Got one of the finished product?

Here ya go Desert Sailor! Oh, by the way, that white stuff piled up there is "SNOW"! :-)



Scroll down about 3/4 ths of the way and you can see the rest of the pics of the shed assembly.

http://s237.photobucket.com/albums/f...III/?start=all

Rick

[Desert Sailor]

Here ya go Desert Sailor! Oh, by the way, that white stuff piled up there is "SNOW"! :-)
Rick

Nice work -- but what is this "snow" of which you speak?

Don't need to worry about snow loads here in Albuquerque, but our spring winds require that this thing be put together reasonably well. So far the "spot steam" treatment is working.

[knottyBuoyz]

Nice work -- but what is this "snow" of which you speak?

Hmmmm? Think of it as very cold and very wet sand that falls from the sky and piles up in your dooryard just to make you miserable for 6 months at a time! *sigh*

Don't need to worry about snow loads here in Albuquerque, but our spring winds require that this thing be put together reasonably well. So far the "spot steam" treatment is working.

Our shed has held up pretty well to 70 MPH wind gusts. Highest sustained winds I'd say we've had is maybe 40 MPH. A little extra diagonal bracing will stiffen it up a lot. Make sure it's well anchored. My biggest fear is wind getting under the thing and it flying off across the neighborhood.

Good luck with your project. Post some pics if you can.

Rick

[Welding Rod]

Only good wood in Abq that is sortable is the dog fir at lowes. Get 14 or 16 foot 2x8 and resaw them. That is what I use to laminate deck beams.

[Desert Sailor]

Only good wood in Abq that is sortable is the dog fir at lowes. Get 14 or 16 foot 2x8 and resaw them. That is what I use to laminate deck beams.

This, or something similar, was the original plan. But a) my table saw is in storage temporarily, awaiting its new home, and b) this project landed in my lap on very short notice and I'm under some significant time pressure (bows have to be finished today, and the structure goes up Saturday morning), and c) I have no help until Saturday.

I'm going to build a bow shed as a shop structure in my back yard, and I may run the numbers on getting 2"x6" or 2"x8" and resawing them, vs. buying more strapping lumber from the mill. So far, planing them down to a real 3/4" and spot-steaming the center 6' is working. But with 4 sticks to go my planer (Delta 12" benchtop) busted a belt last night. The part is on 3 months backorder, no one here has it in stock (hah! does anyone actually stock parts any more?), so I'll work with the full 1", steam 'em, and take a scrub plane to the ends so they'll fit in the bending jig.

Fun, eh? And the winds are supposed to kick up to 25-35 with gusts to 50 this afternoon... ;-)

[seedy]

Hmmmm? Think of it as very cold and very wet sand that falls from the sky and piles up in your dooryard just to make you miserable for 6 months at a time! *sigh*

Rick

Rick, he's pulling your leg a bit, ABQ can have bitter winters. Here's a photo from late April one year...

[Welding Rod]

Yeah! love that sandblaster effect. Got to go secure thing before lunch.

[Desert Sailor]

All the filler blocks are cut. Have to bend 10 bows between now and when the wind kicks in...

[Desert Sailor]

Rick, he's pulling your leg a bit, ABQ can have bitter winters.

Yeah, maybe a little. I grew up in New England, so I remember snow. I also remember moving back to New Mexico from New Jersey, and being very happy the day I sold my big honkin' snowblower... ;-)

[knottyBuoyz]

All the filler blocks are cut. Have to bend 10 bows between now and when the wind kicks in...

I glued & screwed my filler blocks in. It actually went pretty fast.

What are you going to cover it with?

[Desert Sailor]

I glued & screwed my filler blocks in. It actually went pretty fast.

What are you going to cover it with?

4 more bows in the books. Time for lunch. Need fuel.

This shed is a project for a not-for-profit that helps young men make the transition from prison back to a normal life. They help them find jobs, get them back into school, find treatment for alcohol/chemical dependencies, whatever. Batting average is pretty good; probably north of .750.

The shed will be a greenhouse, so we'll cover it with semi-transparent 6 mil greenhouse plastic. The idea is that a) growing their own food makes them a little more economically self-reliant, and b) it's another opportunity to help their clients (re)learn to take responsibility for getting things done.

All privately funded, either by individuals, foundations, or local churches. Doesn't look like much, but they do a good job.

[knottyBuoyz]

4 more bows in the books. Time for lunch. Need fuel.

This shed is a project for a not-for-profit that helps young men make the transition from prison back to a normal life. They help them find jobs, get them back into school, find treatment for alcohol/chemical dependencies, whatever. Batting average is pretty good; probably north of .750.

The shed will be a greenhouse, so we'll cover it with semi-transparent 6 mil greenhouse plastic. The idea is that a) growing their own food makes them a little more economically self-reliant, and b) it's another opportunity to help their clients (re)learn to take responsibility for getting things done.

All privately funded, either by individuals, foundations, or local churches. Doesn't look like much, but they do a good job.

Sounds like a very worthy cause DS.

I had an e-mail from Stimson and he said his sheds are used all over the world. In some countries they're made for disaster shelters, greenhouses, makeshift hospitals etc. You should shoot them an e-mail about your project.

The bows will be a bit rough. If you're putting clear plastic on it you might want to give them a quick sand or a layer of duct tape over them. This should prevent any splinters from piercing the plastic.

Rick

[Desert Sailor]

Sounds like a very worthy cause DS.

I had an e-mail from Stimson and he said his sheds are used all over the world. In some countries they're made for disaster shelters, greenhouses, makeshift hospitals etc. You should shoot them an e-mail about your project.

I would if I had one. Forgive me, but I'm under some serious time pressure -- is there an e-mail address on his website? I don't remember seeing one.

The bows will be a bit rough. If you're putting clear plastic on it you might want to give them a quick sand or a layer of duct tape over them. This should prevent any splinters from piercing the plastic.

The bows that went through the planer are pretty smooth. Those that I had to bend at full thickness (and boy, that was fun!) are pretty rough. If I have time, I'll run the random orbit sander with 80 grit paper over them, just to knock off the really rough stuff.

I'll have plenty of help tomorrow for the actual shed-raising, but today it's just me -- a lot of running around getting materials for sills, stakes, hardware, still need to rip battens, pick up the greenhouse plastic, etc., etc.

[knottyBuoyz]

Go to it man! Git 'er done!

davidstimson@gwi.net

[Desert Sailor]

Go to it man! Git 'er done!

davidstimson@gwi.net

Thanks for the e-mail addy. I'll drop him a note when the project is complete. Someone better be taking pictures.

Lists complete, loading the truck, outta here. Racing the clock. I'll be happy if we get the structure up tomorrow, and the plastic installed on Sunday. And if not, the little bits and pieces left over can be done at convenient times during the week. Yes, I'm talking myself into a less stressful state of mind...

[Desert Sailor]

Update:

The basic structure is up. When this limp noodle wood dries out a bit, it should be plenty rigid. We'll install the plastic tomorrow.

One or two minor things I would do differently next time, but everyone seems pretty happy with it. When I make mine, I think I'll go wider than the 13' we made this one, but for a true greenhouse, this should work out well.

[Mrleft8]

13' seems like a big space until you put up walls a roof and a few people.... Or a boat....
With both cars out of the garage it's a great place for a kid's party..... with both cars in there you need to breathe deep to squeeze between them....... And don't even joke about the contortions you need to do to get through a car door that is only able to open 6"


I think a bow shed with hammer vaults would be fantastic. You could have some nice work space on a second level, lots and lots of storage space, Good points of reference deck height or more, and they just look so cool...

[Desert Sailor]

13' seems like a big space until you put up walls a roof and a few people.... Or a boat....

Boats shrink when they hit the water, and the sheds do seem to shrink once they're up. But this should be large enough. For my shop, maybe 16' or 18' wide, 38' long -- big enough to put the major power tools and have room left for small boat projects.

I think a bow shed with hammer vaults would be fantastic. You could have some nice work space on a second level, lots and lots of storage space, Good points of reference deck height or more, and they just look so cool...

That would be pretty cool. I have to continually remind myself that all the whiz-bang improvements I want to make cost money. A major objective of the implied design brief for the bow shed is minimal $/sq. ft. -- and like options on a car, my "improvements" will just jack up the final price tag. It's mighty tempting -- must resist...

[Mrleft8]

(Insidious image posted purely to cause day dreams...)

[Desert Sailor]

Update:

The greenhouse is complete. The basic framework went up Saturday. Hardest part was connecting the second set of bows to the ridge pole. The wet noodle wood was twisting all over. We had ratchet straps horsing the ridge pole into something close to a straight line, and more on individual bows to bend them back straight (or close).

Horizontal and diagonal strapping, and end framing all went up in the afternoon. The diagonals were cobbed up a bit, given the inconvenient spacing of the filler blocks. Sunday morning we hung the plastic, despite the fact that the plastic team rolled it in the wrong direction. Made for some interesting photo ops as I crawled along the ridge pole nailing down the last two battens.

Nice feature of the semi-wet wood was that staples penetrated fairly easily -- made hanging the plastic before battening down a bit easier.

A few things I'll do differently on the next one. But I'm pretty convinced that a slightly modified/enlarged bow shed would make a very serviceable shop that would not require loans or loading up the credit card.

[Mrleft8]

A few things I'll do differently on the next one. But I'm pretty convinced that a slightly modified/enlarged bow shed would make a very serviceable shop that would not require loans or loading up the credit card.

[Desert Sailor]

Mrleft8 -- now you're just being mean ;-) I've often thought about my shop as a personally sacred space, but this might be a little hard to sell to my wife...

[Mrleft8]

Cruelty is becoming a passion with me!
I really would like to build a barrel vault/hammer beam building some day....
There's just something so curiously beautiful about the lines that are created....
Of course, it may just be that the ugly ones are never photographed.....

[Dan McCosh]

Looks like you could end up turning it upside down and make it into an ark.

[knottyBuoyz]

Looks like you could end up turning it upside down and make it into an ark.

That has been suggested to me a few times with my shed! :-)

[MN Dave]

Looks like you could end up turning it upside down and make it into an ark.

DGentry does it all the time.


Back to the original problem of snapping frames...

Would a Gothic arch be a better design with it's much larger radius in a similar size? The Gothic arch has a circular arc instead of a variable radius arc with a fairly flat section across half the width of the roof. 'The classic Gothic arch is known as the quinto acuto or "pointed fifth". The arcs are 4/5 of the span. The centres of the arcs are inside the span of the arch.' So the center of the arc is 1/5 of the width from each side.

There was a link to a plan in an old post that looks similar to the Stimson Marine design. Scaling off the pdf, That plan for a 21 ft. wide, 13 ft high bow shed has a minimum bend radius of about 9-10 ft. A Gothic arch 21 ft wide and 15 ft. high would have a bend radius of 16.8 ft, which should be a lot less likely to break. There is more room higher up and no loss of space lower down.