elliptical apron glue-up (miserable failure!!)

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Forum topic by Ben posted 08-08-2010 12:29 AM 1168 views 0 times favorited 8 replies Add to Favorites Watch
View Ben's profile


242 posts in 2276 days

08-08-2010 12:29 AM

hey guys,
well, have spent a lot of time reading and looking at pictures of tables.
spent the entire day today making the apron form out of MDF.

here’s what i did:

layed out with string and nails. rough cut with jigsaw, sanded to line with belt sander and hand sanded as near perfect as i could see.
then i cut out another one and routed it flush with the router, stuck together with double-sided tape.
then i made two more stacks at each of the bends, to make 3” thick in four separate pieces, with a little bit of space between each. these were screwed down and routed flush.

i then ripped 3” strips of “whacky wood.” luckily, an 8’ strip goes entirely around my diameter with room to spare.
i layed out all three strips dry, clamping and marking in place each course for length.

i brad nailed the first piece at the joint, pulled nice and tight.

then i slathered the two remaining pieces with glue and attempted to bend them on and clamp them up.
i started in the middle and began clamping.

i had dripped some holes in some places to allow the clamp to be perpendicular to the bend.

somehow, there are huge gaps all over the place where the plys have been squashed out of the intended shape and are not even touching the form in some places, i would say about 3/16” in some places.
the glue started to set up on me before i could finish, too. the shape is noticeable “whacky” to the naked eye.

so, i would say this go around is a total failure. i’m not sure what i did wrong, but obviously there is a better way to do this, eh?

should i have lammed all three plys together first, then start clamping it on?
should i use a screw or two to get the thing held in place and started?

i ran out of titebond III about half way and had to use regular titebond.
am feeling pretty depressed to see all my efforts for the day down the tubes.

any advice for how to continue would be appreciated.

i think i can still use the form, and i’ll get some better glue.

what do you think of using ratcheting band straps instead of clamps, or in addition to clamps?
any tips for accurately measuring the length of each piece, and how do you account for the thickness of the glue?

i know this is cheesy, but what about simply screwing all three plys to the form at intervals, then removing the screws after glue is cured, filling holes and gluing on the veneer?

it seems that for all the time i spent messing around with the form and trying to glue today, i could have built the apron in brick-lay style and been done by down. not sure…
thanks guys.

8 replies so far

View douginaz's profile


220 posts in 3421 days

#1 posted 08-08-2010 01:00 AM

Wow, I wish I had some words of wisdom or had a “aha” moment when I could pick something up from your story – doesn’t seem to be the case. I wish you well and am damned sorry I can’t help. I feel for you dude – keep at it, I’m sure someone here will be able to help you along the path of happy destiny.
Doug in AZ.

-- If you need craft books - please visit our small business at

View KayBee's profile


1083 posts in 2665 days

#2 posted 08-08-2010 01:46 AM

You might consider making an ‘outside’ form. Then you just sandwich the layers in between both forms. Drill holes in both for clamps to pull everything together. One thing I’ve learned(only thing :)) about glue ups like this is no matter how much glue you think you’ll need-you’ll need more. Good luck and keep us posted.

-- Karen - a little bit of stupid goes a long way

View huff's profile


2828 posts in 2704 days

#3 posted 08-08-2010 03:43 AM

beevis, Sounds like you did a really good job building the form, and also sounded like you got a good fit with the first layer of bendable plywood around the form. First, make sure you use a very slow setting glue. Only work one layer at a time. Start at one end and slowly clamp it around the form and the first layer. Trying to glue and clamp two layers at the same time caused the two layers to fight each other. You where trying to work two (actually 3) different radiuses at the same time. each layer is a different radius. Once you get your second layer glued and clamped, leave and let dry. Then you can work your third layer. You won’t be able to laminate the layers first and then clamp to the form, again each layer has to follow a different radius, so if you glue them together flat and then try to form them, it won’t work. Once you have the three layers glued and it dries, you should be able to remove your form and it will hold its shape. Let me know if I can help you more. Good luck

-- John @

View Ben's profile


242 posts in 2276 days

#4 posted 08-08-2010 03:55 AM

thanks guys.

so huff: how do i keep the first layer against the form? like i said i shot a few brad nails at the joint, and was planning on either being able to wrangle the whole thing out and brake it away from the nails, or drill/chisel out the nail.
there has to be a better way, though…

so you’re saying put on the first layer, then glue the second layer to it, clamp and let cure overnight, then do the third layer?

is it OK to use two ratcheting straps as clamps?

i have a bunch of C clamps, too, but it seems like i can only put one clamp in the middle of the 3” strip, as opposed to top and bottom.

thanks a lot.

View Ger21's profile


1047 posts in 2550 days

#5 posted 08-08-2010 04:36 AM

Use an additional strip as a caul, and use 3” high blocks at all the clamps to distribute clamping pressure as much as possible. Best is a series of outer forms to get fill clamping pressure around the entire outside.

Sounds like you really need more clamps, though.

Are you trying to glue an entire ellipse in one piece? That’s an extremely difficult glue up, especially for a first try.

-- Gerry,

View rance's profile


4243 posts in 2579 days

#6 posted 08-08-2010 04:59 AM

A picture is worth 1000 words. You lost me at the point where you dripped some holes. Sorry. Got any pictures?

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

View Ben's profile


242 posts in 2276 days

#7 posted 08-08-2010 04:48 PM

thanks again guys.
Ger21: yes, i am trying to glue an entire ellipse in one piece. i thought it would actually be easier in solid pieces as opposed a bunch of shorties.

thanks for the square recommendation. i do think that’s what the problem was, mostly. i had two strips and started in the middle of the outer one (the inner one was the end of a piece). and it just got all screwed up as i went along.

i think i’m going to try one a time, start at one end with a square line, and use straps instead of clamps.

thanks a lot. i’ll keep you posted.

View Ben's profile


242 posts in 2276 days

#8 posted 08-08-2010 07:50 PM

hey guys,
well, i just finished round II on the apron glue-up and it’s looking MUCH, much better.
here’s what i did:

clamped and pulled the first piece as tight as i could. did this a few times to make sure.
then i brad nailed in both ends at the joint. i shot the nails top and bottom at an angle so they shot out the top and bottom of the form. this way at the end i can simply pull them out from behind with a vice grips.

i then clamped and pulled the second piece as tight as i could, a few times.

then i went out and bought more titebond III, and made a mix with a little bit of water. i read about another guy doing this to help the boards “slip” past each other. it definitely seemed to help, and also seemed to give me more working time. i was able to get the piece slathered and installed in probably less than 10 minutes. whereas yesterday i spent all my precious time fiddling with clamps and by the time i was half way around it was shot.

i slathered with glue,i clamped one end onto the form following my square line (thanks for that tip), wrapped it around as tight i could, clamped the other end temporarily, and then slid on my two ratcheting cargo straps.
all i can say is “AWESOME.” the straps are totally the way to go on this. i cranked them tight and it sucked the second piece tight all the way around. when i had it fit by hand, there was about a 1/4” gap at the joint, and the straps pulled them tight.

so both straps gave me a pretty good uniform squeezeout all the way around. in a few spots i added a few strategic clamps with a piece of plywood to protect the face.

so it’s looking really really nice now, finally.
in a few hours, i’ll take off the straps and add the final piece in the same way. then i’ll add the veneer.
i think the “whacky wood” is inherently not so perfect to work with. around my tight radii the outer veneer wants to split, and it winds up bulging out. not good.

how should i apply the final veneer?

thanks for all the feedback. it’s helped a lot.

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