Page 1 of 2 12 LastLast
Results 1 to 15 of 17

Thread: panel glue up ?

  1. #1
    Join Date
    Jan 2009
    Location
    Indianapolis
    Posts
    760

    panel glue up ?

    Last time I glued up a couple pieces for some tall drawer faces @ 10" I have some cupping across the face. I am sure the faces were flat and edges were 90 before glue up. I cut it down to @ 7-1/2 and then had enough thickness left to joint a face flat, but could to much pressure on the clamps cause this?

    Thanks.

    Brian
    Brian

  2. #2
    Join Date
    Dec 2021
    Location
    Southwest WI
    Posts
    244
    I'm not sure about the clamping pressure but if all the clamps were on one side I could see that possibly happening. I have had similar issues when I didn't let wood acclimate to my shop environment prior to surfacing. You can also alternate the growth rings to help prevent cuping.

  3. #3
    Did you glue it up thicker than your finished size then plane to finished size?

    Also, Alternating the faces that ride on the jointer fence can equalize even the slightest error in fence squareness.

    If you had to clamp it really tight to get it to pull tight I would think that could cause it to cup.

    Cupping from drying would look different than a gle edge angle problem.

  4. #4
    Did you glue it up thicker than your finished size then plane to finished size?

    Also, Alternating the faces that ride on the jointer fence can equalize even the slightest error in fence squareness.

    If you had to clamp it really tight to get it to pull tight I would think that could cause it to cup.

    Cupping from drying would look different than a gllue edge angle problem.

  5. #5
    Join Date
    Jan 2009
    Location
    Indianapolis
    Posts
    760
    Quote Originally Posted by Mitch schiffer View Post
    I'm not sure about the clamping pressure but if all the clamps were on one side I could see that possibly happening. I have had similar issues when I didn't let wood acclimate to my shop environment prior to surfacing. You can also alternate the growth rings to help prevent cuping.
    Wood was acclimated and it rested between steps. Bessey clamps, alternate orientation every other one?
    Brian

  6. #6
    Join Date
    Jan 2009
    Location
    Indianapolis
    Posts
    760
    Quote Originally Posted by Ron Citerone View Post
    Did you glue it up thicker than your finished size then plane to finished size?

    Also, Alternating the faces that ride on the jointer fence can equalize even the slightest error in fence squareness.

    If you had to clamp it really tight to get it to pull tight I would think that could cause it to cup.

    Cupping from drying would look different than a gle edge angle problem.
    Yes thicker at glue up rejoined and planed to final after. Didn't seem that tight, but maybe...thanks brian
    Brian

  7. #7
    Quote Originally Posted by Ron Citerone View Post
    Did you glue it up thicker than your finished size then plane to finished size?

    Also, Alternating the faces that ride on the jointer fence can equalize even the slightest error in fence squareness.

    If you had to clamp it really tight to get it to pull tight I would think that could cause it to cup.

    Cupping from drying would look different than a gle edge angle problem.
    YEP, and when you are planing take more wood off the side that has the “ hill” in the middle. Lot of times you can immediately see the
    other side move too. For critical stuff some will do ‘face and plane” leaving material thick, then stop and lean the pieces against something and let them
    sit over night. But most of time ….there is NO time. Never put a panel on a surface ,while the other side is open to the air, Unless you are
    trying to “fix” cupped piece. Alternating the
    faces on jointer ,and marking them make for flat panels, too many spend time squaring a jointer face that is gonna immediately flop to its favorite angle.

  8. #8
    Join Date
    Dec 2021
    Location
    Southwest WI
    Posts
    244
    Quote Originally Posted by Brian Runau View Post
    Wood was acclimated and it rested between steps. Bessey clamps, alternate orientation every other one?
    Even with parallel clamps i still alternate every other clamp from top and bottom. I also try to alternate the direction the end grain radius for lack of a better term (think smile up smile down when looking at the end grain)

  9. #9
    Join Date
    Jan 2009
    Location
    Indianapolis
    Posts
    760
    Quote Originally Posted by Mel Fulks View Post
    YEP, and when you are planing take more wood off the side that has the “ hill” in the middle. Lot of times you can immediately see the
    other side move too. For critical stuff some will do ‘face and plane” leaving material thick, then stop and lean the pieces against something and let them
    sit over night. But most of time ….there is NO time. Never put a panel on a surface ,while the other side is open to the air, Unless you are
    trying to “fix” cupped piece. Alternating the
    faces on jointer ,and marking them make for flat panels, too many spend time squaring a jointer face that is gonna immediately flop to its favorite angle.
    I don't like lay them flat, I do use spacers so air can circulate, and they sit overnight after face jointing and light plane pass, then next day flatten again and then plane. Thanks brian
    Brian

  10. #10
    That isn't a big glueup. I am surprised at the result. Are you sure the edges were at right angles to the faces? That could cause cupping. The wood drying out after glueup could too. I do not alternate growth rings, I orient the boards for appearance, and I often make much wider glueups. My two most recent projects are a couple coffee tables with cherry tops that are over 20 inches wide. Three boards in one and four in the other. Wood was planned to final thickness before glueup with cutting to final size and sanding the only remaining steps before finish. No problem with either. These are just my most recent projects, I did a 10 foot long dining table the same way last year. A large chest of drawers was also completed last year. No issues with any of these either.

    I almost never use my jointer to prepare the edge of boards for glueup. For shorter ones, I just rip them on the table saw. For longer ones or if I'm having an issue, I use my track saw. It does a great job of giving me straight edges at right angle to the face. I know this is not traditional but it works for me.

  11. #11
    Join Date
    Jan 2009
    Location
    Indianapolis
    Posts
    760
    Quote Originally Posted by Jim Dwight View Post
    That isn't a big glueup. I am surprised at the result. Are you sure the edges were at right angles to the faces? That could cause cupping. The wood drying out after glueup could too. I do not alternate growth rings, I orient the boards for appearance, and I often make much wider glueups. My two most recent projects are a couple coffee tables with cherry tops that are over 20 inches wide. Three boards in one and four in the other. Wood was planned to final thickness before glueup with cutting to final size and sanding the only remaining steps before finish. No problem with either. These are just my most recent projects, I did a 10 foot long dining table the same way last year. A large chest of drawers was also completed last year. No issues with any of these either.

    I almost never use my jointer to prepare the edge of boards for glueup. For shorter ones, I just rip them on the table saw. For longer ones or if I'm having an issue, I use my track saw. It does a great job of giving me straight edges at right angle to the face. I know this is not traditional but it works for me.
    These are drawer faces for a dresser @ 7.25 x 39. Thanks brian
    Brian

  12. #12
    Join Date
    Nov 2012
    Location
    North Dana, Masachusetts
    Posts
    366
    What was the moisture content of the wood, and what is the humidity level in the shop?

  13. #13
    Join Date
    May 2018
    Location
    Lancaster, Ohio
    Posts
    987
    Quote Originally Posted by Brian Runau View Post
    Wood was acclimated and it rested between steps. Bessey clamps, alternate orientation every other one?
    yes, really easy to end up with a cup if you don't alternate
    Ron

  14. #14
    It's hard to know from your description whether the problem is inaccurate joints, clamping technique or change in moisture content. A dry run in clamps using a straightedge would tell you a lot. If you are using a jointer, alternate the consecutive faces against the fence, otherwise ensure that the edges are consistently at 90*. You can throw off an accurately cut joint with unbalanced clamping - setting a straightedge across the glued assembly will help avoid that, as will alternating clamps on either face. If the surfaces between the joints are cupping (curving across the grain) it is from moisture loss or uptake so you need to allow the stock more time to acclimate or make the humidity in the shop more consistent. That sort of cupping is not caused by clamps.

  15. #15
    Join Date
    Apr 2017
    Location
    Michigan
    Posts
    2,222
    Too much clamping pressure could have caused some crush in the joint, messing up your careful edge prep.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •