bowed board

[charlie spencer]

i needed a pair of 1x4 pine boards 7 feet long. True 1x4's not 3/4 x3 1/2. I went to a big box store and selected a straight, kiln dried 2x12 with tight vertical growth rings and ripped two boards from the edges and planed down to 1". They looked great for one day before they bowed about a half inch. Suggestions please.

[Brett Luna]

Did you plane from both sides equally? Planing more from one side than the other can allow internal tension to create a bow. Cutting a wide board down can also result in some movement. Also, when it comes to the big box stores, even kiln dried wood can have a significant amount of moisture in it.

[glenn bradley]

I made a workbench base out of kiln dried construction limber from the BORG. It continued to move even after months of acclimating in the shop and assembly. Does it have to be pine? Poplar from a reliable lumber yard was what I used on the next bench and it was great to work with.

[charlie spencer]

Did you plane from both sides equally? Planing more from one side than the other can allow internal tension to create a bow. Cutting a wide board down can also result in some movement. Also, when it comes to the big box stores, even kiln dried wood can have a significant amount of moisture in it.


I planed both sides about equally but stress appears to be the problem. I hate to think about the cost of finding these boards. They will be more expensive than teak.
thanks

[charlie spencer]

Thanks, I do need pine to match a piece. This is a bear.

[Lee Schierer]

Generally speaking, construction lumber is kiln dried only to about 12% moisture. That is not sufficient for stability. If you want to try again, take the lumber home and stack it with weights so it can't move and wait a month or two before doing anything. Then slowly (several days or even a week between sessions, remove only a small amount of material from each face until you reach your finish size. Keep the material weighted down between sessions.

[John TenEyck]

More likely it's around 20% MC. Regardless, you have to let the board sit in your shop for weeks/months before resawing or it will banana chip. A better solution is to go to or call a real lumber supplier and buy true KD 5/4 or 6/4 rough sawn pine and plane it down to whatever you need.

John

[Robby Tacheny]

Charlie,

Would you mind telling us what project these are being used for? Bow can be worked around, depending on the circumstance.

Robby

[Prashun Patel]

I think BORG sells 5/4 stock in 5" or 6" (nominal) width in. It's sold in the pine board section. I'd buy those instead. I've had very good luck with the pine boards from HD. Select from a bundle that's had the plastic zip strap removed, so the pieces have had time to release tension and reveal their true colors.

I don't trust construction lumber from anywhere around me. The few lumber yards I've been to around here don't take greater pains to protect their stock, and frankly they're roll-yr-eyes snobs who hate the fact that I only need a couple pieces and will drive it in my sedan.

[Michael Weber]

, and frankly they're roll-yr-eyes snobs ..
Roll-yr-eyes, :D Hilarious

[J.R. Rutter]

Like Lee and John mentioned, it is moisture that is most likely the root cause of your problem. Tension is pretty apparent immediately while ripping. Uneven moisture loss as the board loses moisture to reach equilibrium causes movement after milling where the board was pretty straight and flat initially. If the wood is laid flat on one face, it will tend to bow up at the ends/edges as that face loses moisture and shrinks. If you flip it over, it may come back to flat and even bow in the other direction.

[Bradley Gray]

An Antique dealer taught me an old trick- lay the board in the grass in the sun convex side down and keep an eye on it for an hour or two. He used this method for loose shelves and table leaves with good results.

[Chris Fournier]

More likely it's around 20% MC. Regardless, you have to let the board sit in your shop for weeks/months before resawing or it will banana chip. A better solution is to go to or call a real lumber supplier and buy true KD 5/4 or 6/4 rough sawn pine and plane it down to whatever you need.

John

Agreed! Construction lumber around here is never 12% more like soaking wet...

[charlie spencer]

Charlie,

Would you mind telling us what project these are being used for? Bow can be worked around, depending on the circumstance.

Robby


I am restoring an antique screen door, specifically replacing the rails(1x4x84) actual size. I need vertical grain for stability and visual.

[Robert Engel]

It all about moisture and the fact its construction grade lumber. You might try cutting your material to width take a couple passes, and let it dry for a week.
That can be tough this time of year if the humidity is high.

If you don't want to mess around with it, then go to a hardwood dealer and see what they have.

You might also consider building up the board from 1X material using a non flexible glue like epoxy.

If you face glue the boards and keep them clamped flat, it should work.

[Robby Tacheny]

I found a couple of reclaimed wood places in/near Birmingham AL. Maybe you can get lumber with the dimension you need which won't require planing? I have seen oak barn boards that were straight and hard cup and warp after face planing. Just too many variables. Also, you are in one of the most humid times of the year.

Robert's idea is sounds pretty good to me. Could you get two pieces of 1/2" lumber and face glue them together to help with rigidity and get you to 1"?

Robby

[lowell holmes]

I had to save a big piece of walnut I bought to make a boardroom door. IIRC, it was 10" wide and 8 foot long. I ripped the board down the middle.

I then glued the boards together with the bow opposite. IIRC, I placed dowels in the blue joint on 8" centers. The door was 48" x 80". It never did fail.

[Jon Endres]

See if you can find a lumberyard that sells clear vertical grain douglas fir. I know you are trying to save a few bucks but this is one application you should probably find the right lumber for the job. While the 2x12 you bought may have also been doug fir, you released the internal stress in the board by ripping "quartersawn" pieces off the sides. I used to see this a lot with flitch-sawn lumber coming off my sawmill - the boards would often crack through the heart and move an inch or more within 24 hours.

[J.R. Rutter]

See if you can find a lumberyard that sells clear vertical grain douglas fir.

5/4 VG fir is less than $5 / BF here. But 84" is tough to get truly flat. Need lots of patience and incremental milling.

[charlie spencer]

It all about moisture and the fact its construction grade lumber. You might try cutting your material to width take a couple passes, and let it dry for a week.
That can be tough this time of year if the humidity is high.

If you don't want to mess around with it, then go to a hardwood dealer and see what they have.

You might also consider building up the board from 1X material using a non flexible glue like epoxy.

If you face glue the boards and keep them clamped flat, it should work.

good suggestion, but that is what i have wanted to avoid.
thank you

[lowell holmes]

5/4 VG fir is less than $5 / BF here. But 84" is tough to get truly flat. Need lots of patience and incremental milling.

That's a good reason to try my solution. You have nothing to lose, and it did work for me.

[Bill McNiel]

5/4 VG fir is less than $5 / BF here. But 84" is tough to get truly flat. Need lots of patience and incremental milling.

Boy what a difference 100 miles makes. VG fir is over $7 / BF in Seattle.