Simultaneous glue-up concerns

March 2, 20151 Comment

gang glueup

It’s not unusual in the basement workshop to find myself doing simultaneous glue-ups on identical components, in fact I do it quite frequently. Typically the reason is because of a lack of clamps, and a strong desire to make progress on the project as quickly as possible.

If I stepped back and paid close attention to the amount of time I spend creating a strategy for just how it is I’ll accomplish the task I’d probably discover I spend way too much time overthinking it.

The reason I’m writing about this topic is because a viewer on my YouTube Channel had a question about it, and a couple of others regarding the glue-up process and results.

I thought they were important questions to ask and answer, so rather than just replying in the comments over there, I decided to share them here.

“When you gang the interior frames for the glue up aren’t you worried about glue setup, squaring and even clamping pressure?”

Yes, I am worried about the possibility of the glue-up and clamping process causing the components to become unsquare.

To help minimize this as much as possible I spent a fair amount of time doing test fits and dry-runs prior to the actual glue-up. Inevitably it won’t guarantee there won’t be issues once the glue is applied, but it’s a great way to get a feel for what you’ll have to do to get a successful glue-up.

Not to mention, it’s also an opportunity to discover if any joinery needs to be tweaked.

Did I discover any issues? Yes I did actually, they weren’t severe enough to warrant filming and discussing (at least in my opinion they weren’t) but all it took to resolve them was to breakout my shoulder plane and adjust the shoulders on a short rail or two.

It turned out while I was routing the tongue on each end, one or two weren’t as square as I had thought they were originally. To fix it was a matter of using my square to identify the high side and then removing a little bit of material from that end and repeating the test fit until it all lined up square.

applying web clamp

My choice to use the web clamps made the glue-up even easier as once I had the joinery squared I was able to put everything into place, then wrap the clamps in position. And really they did all the work of aligning the parts together for me. On top of it, the web clamp’s corners were wide enough to support the entire thickness of the two frames completely.

“Invariably, there will be slight dimensional differences between the frames that may make the clamping pressure uneven between them. Also, since the bottom piece is obstructed by the wax paper, isn’t it difficult to ensure the bottom piece is square as well as the top piece?”

Since the clamp corners were only on the ends, I was slightly concerned about the middle rail. I had a straight clamp ready to be added in case it was necessary, but in this case it wasn’t.

If in the end I had discovered there were issues with square I would have grabbed a long pipe clamp or two and applied them diagonally from corner to corner to pull it square, but as we all saw, the web clamps did their job (thanks to the square joinery.)

square frame

In the video, when I checked for square I had actually pushed one frame proud of the clamp’s face, afterwards I carefully pushed it back down into position.

Because they both lined up so evenly with each other, I took a gamble that they would both be square as a result. Turns out it was a gamble that paid off in the end.

“Finally, by the time you’ve assembled the second piece hasn’t the glue started to set on the first?”

I can’t tell you how much I’ve worried about this scenario over the years. I’m simply going to assume it’s due to my woodshop’s environment, but I typically have a good 10-15 minutes of open time with most PVA glues I’ve used (I used Gorilla Glue’s white PVA glue in this build.) Even though it’s super dry this time of year in my shop, there was still plenty of open time that allowed me to apply the glue, assemble and then adjust components into position.

This is also where previously doing a dry run and test fitting the components ahead of time helps too. It’s not only about double checking the fit and joinery, it’s also about creating a strategy for how it should come together and discovering where you might trip up and how to get around it.

Does it guarantee a flawless glue-up everytime? No, but it sure helps to minimize the amount of anxiety and the unknowns in your glue-up process for complex pieces.

Do you have other questions? Please don’t hesitate to ask by leaving them in the shownotes or using the form on my contact page here at the website.

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  1. Eric R says:

    Great post Matt.
    (Great questions too.)
    I think with experience and enough practice, along with always doing a dry fit, the anxiety level gradually reduces.
    Pretty cool way you got that glue up all together so nicely.
    (“The power of the beard”)…

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