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Forum topic by Mike2004dales posted 07-26-2013 09:17 AM 742 views 0 times favorited 14 replies Add to Favorites Watch
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Mike2004dales

3 posts in 486 days


07-26-2013 09:17 AM

Topic tags/keywords: warping lumber panels help glue ups oak rough cut question

Just joined lumberjocks and am a huge fan! I’m somewhat new to the woodworking scene. Recently, I started a pantry for my grandparents. The front is going to be two raised panel doors. I prepped all the wood last night which included two sets of stiles, 6 rails ( 2 panels per door) and 4 glued up panels. I got home today to find that my panel on top of the stack had bowed ao that about 1/8” gap is visible on each side! And the same with my top stile! I took rough oak from my stack I picked up about 2 weeks ago and planed it down last night and made the panels. So my question is what went wrong? Was it me? Or the lumber not as dry as it should have been? And what do I do to avoid this? Thanks for any answers or info you all have for me!


14 replies so far

View OhioMike's profile

OhioMike

53 posts in 882 days


#1 posted 07-26-2013 10:16 AM

I’d say you’re right to question the moisture content of the oak. Did the seller say it was kiln dried?

You said you bought it 2 weeks ago. Has it been in the shop that whole time or was it stored some place with different humidity and temperature such as a garage or back-yard shed?

To minimize the risk, many woodworkers bring the wood into the shop days or even weeks ahead of time and place the wood “on sticks” to allow air to circulate around it so the temperature and moisture content can equalize with your shop.

For additional insurance against warping you can cut, joint and plane the parts to rough size and put them back on sticks again for a few days before completing the project.

Sadly, a small percentage of the wood we buy is simply going to misbehave no matter what we do. Let’s hope your oak is not in this category.

View Marcus's profile

Marcus

1077 posts in 739 days


#2 posted 07-26-2013 11:48 AM

Mike’s answer pretty much sums everything up and not sure there is much more to say. I would just echo what he said about letting the lumber acclimate for a couple weeks, rough cut, give it another week, and then do your final planing, jointing, and dimensioning.

Good luck w/ the project and welcome to the boards.

View kizerpea's profile

kizerpea

746 posts in 1087 days


#3 posted 07-26-2013 12:01 PM

Yup that’s common with air dryed wood.

-- IF YOUR NOT MAKING DUST...YOU ARE COLLECTING IT! SOUTH CAROLINA.

View Bluepine38's profile

Bluepine38

2937 posts in 1805 days


#4 posted 07-26-2013 01:39 PM

Agree with the above statements, some cabinet makers used to store wood for a year or longer before use,
unless they knew the supplier and his seasoning practices very well, then a month to let it acclimatize would
do. This is not usually possible now, but we have to do the best we can.

-- As ever, Gus-the 75 yr young apprentice carpenter

View joeyinsouthaustin's profile

joeyinsouthaustin

1285 posts in 792 days


#5 posted 07-26-2013 02:52 PM

I also rest the pieces between milling phases, to find the “wild wood”

-- Who is John Galt?

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joeyinsouthaustin

1285 posts in 792 days


#6 posted 07-26-2013 02:53 PM

Another ? did you oppose grain on the panel glue ups? I am assuming that bowed is used properly, rather than cupped?

-- Who is John Galt?

View Nomad62's profile

Nomad62

726 posts in 1678 days


#7 posted 07-26-2013 03:25 PM

Oak is notorious for this. If kiln dried improperly it will build tension (case-hardening) that will not go away until it is sliced, often times ruining the wood altogether. Some people get oak too thick to then slice 1/4”or so from all the sides, making the tension much less. You’ll find oak that will bend right in and pinch on your bandsaw blades if you use it enough. No way to look at it and tell, just need to find a source that sells properly dried wood. Cannot say that is the case here as it’s only a verbal forum, but it happens. Ask your sales point if they can warrantee their wood from case-hardening, or maybe buy a small piece to test cut it.

-- Power tools put us ahead of the monkeys

View birdsandboards's profile

birdsandboards

7 posts in 487 days


#8 posted 07-26-2013 03:33 PM

+1 to previous replies. One thing we do at the cabinet shop I work at is weigh down all the panels at the end of the day. Put them on a flat surface and put 3/4 plywood over them weighed down with sandbag, etc. Not exactly how well it works or if its done just to make us feel better.

View Rick M.'s profile

Rick M.

4322 posts in 1100 days


#9 posted 07-26-2013 03:44 PM

panel on top of the stack had bowed

Wood moves through the addition or subtraction of moisture. When you stacked the wood you cut off air contact to one side but not the other, the top of the panel lost more moisture and bowed.

-- http://thewoodknack.blogspot.com/

View Mike2004dales's profile

Mike2004dales

3 posts in 486 days


#10 posted 07-26-2013 06:45 PM

Photobucket Pictures, Images and Photos

That’s what happened. I believe that’s cupping not bowing now that I think about it. They were supposed to be 5/8” panels for a door. Are they still usable as raised panels?

View Monte Pittman's profile

Monte Pittman

15104 posts in 1058 days


#11 posted 07-26-2013 07:02 PM

My guess is also moisture. Normally for me, it’s not a problem. This year our humidity has been 3-4 times higher than normal. I have never had this many problems with wood moving on me.

Welcome to LumberJocks

-- Mother Nature created it, I just assemble it.

View joeyinsouthaustin's profile

joeyinsouthaustin

1285 posts in 792 days


#12 posted 07-26-2013 09:30 PM

It appears one board is a glue up, and others not or all glue up?? The reason I ask.. the board that I can tell is glued up has the grain cupping in the same direction. I believe you need to oppose the grain.. the arch created by the grain, that you can see in the end grain, should be opposite each other, when gluing up panels. It will always want to cup in the direction of the “legs” of the arch. This can be mitigated by opposing that action. You can use this, and smaller rips to glue up more stable panels, especially when using straight sawn boards. Using Quarter saw oak will also mitigate this. You will notice the board with the most “arched” grain cupped the most. I hope this is helpful. When doing larger panels grain selection and panel layup can be quite important, as well as sticking, resting, and milling extra.

-- Who is John Galt?

View Mike2004dales's profile

Mike2004dales

3 posts in 486 days


#13 posted 07-26-2013 10:29 PM

They are actually all glued up. Just 2 small panels. Thanks for all the feedback. I will chalk it up to a lesson learned about wood grain haha. So would it be safe to say you should avoid tight grained boards for panel glue ups?

View WDHLT15's profile

WDHLT15

1184 posts in 1196 days


#14 posted 07-27-2013 02:07 AM

No, tight grained boards are fine. Quartersawn grain is the most stable. That is where the growth rings run perpendicular to the face of the board. Flatsawn boards tend to be more prone to cup. That is where the growth rings run parallel to the face of the board. Wood will naturally cup toward the bark side of the board. However, if you lay a panel flat, air can only get to one side, and that is the side that will either dry more or pick up moisture from higher humidity like at night, increasing the chances for cup.

So, never lay a panel on a work bench or flat surface and leave it. Make sure both sides can get air. I simply lean them on the side of the bench where both sides can get plenty of air. That will keep the panel more stable until you get it into the rails and styles if you are in the middle of construction.

Another thing that I learned the hard way is to make panels and table tops last. The tendency is to make them first because that is the nicest wood and the most fun part of the project. Now, I make tabletops the very last step and attach them relatively soon after they are made.

-- Danny Located in Perry, GA. Forester. Wood-Mizer LT15 Sawmill. Nyle L53 Dehumidification Kiln

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