Glue Myths No. 3 - Biscuits

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algale
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Glue Myths No. 3 - Biscuits

Post by algale »

Even though the biscuit joint's reputation had begun to suffer some years ago, this is still an interesting video.

https://www.youtube.com/watch?v=8G2Z5iUN4gw
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Re: Glue Myths No. 3 - Biscuits

Post by RFGuy »

Thanks Alan! Very interesting. Looks like that weak side-to-side grain joint is to blame again! Hopefully he will evaluate domino strength next.
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Re: Glue Myths No. 3 - Biscuits

Post by DLB »

I didn't care for this one, but enjoyed the other two. The only myth busted here, I think, is that biscuits are an easy and convenient way (compared to splines) to strengthen a joint with a product whose grain runs across (through) the joint. (Paraphrasing the early part.) But I think Mr. Sullivan created that myth at the beginning of the video. Once he busted that myth, by showing that biscuit grain does not run across the joint, he should have switched to splines for the miters and tenons or dowels for the end-butt.

The most common uses of biscuits in my shop are for edge-to-edge or edge-to-plywood. I'm very curious as to why biscuit testing for an edge-to-edge glue-up was not included in the video. Seems to me to be the most relevant and most important, as this was the weakest joint in his first video in the series due to wood failure, not joint failure.

- David
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Re: Glue Myths No. 3 - Biscuits

Post by RFGuy »

David,

Yeah, I agree. I don't think this video was as much of a surprise for the result. The video before this one was where he tested miters, so I think he saw this one as a continuation of that one but with biscuits. It would be informative if he followed this up with miters with splines at different grain orientations of the spline. Or, miters with Dominos in them. Another thing not really covered in his video is the biscuit joint itself. It is my understanding that a lot of biscuit cutters on the market don't do a good job of cutting the biscuit slot, essentially making it too wide so the biscuit fit is sloppy. I don't know how much of a difference this would make, but I would think it is a factor. Also not being discussed is that commercial biscuits are of rather poor construction in my opinion. A properly oriented solid wood spline should be stronger IMHO.
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Re: Glue Myths No. 3 - Biscuits

Post by edma194 »

DLB wrote: Mon Oct 18, 2021 12:57 pm The most common uses of biscuits in my shop are for edge-to-edge or edge-to-plywood. I'm very curious as to why biscuit testing for an edge-to-edge glue-up was not included in the video. Seems to me to be the most relevant and most important, as this was the weakest joint in his first video in the series due to wood failure, not joint failure.

- David
This is what I thought biscuits were specifically for, long edge to edge joints, and mainly to prevent separation. I don't see how the additional glue area from a biscuit would have mattered in this test either, it's not additional glue area between the two pieces.
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Re: Glue Myths No. 3 - Biscuits

Post by HopefulSSer »

A week later he reconsiders his initial opinion somewhat:
https://woodworkingformeremortals.com/i ... i-thought/
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algale
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Re: Glue Myths No. 3 - Biscuits

Post by algale »

HopefulSSer wrote: Mon Oct 18, 2021 5:42 pm A week later he reconsiders his initial opinion somewhat:
https://woodworkingformeremortals.com/i ... i-thought/
Different guy.
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Re: Glue Myths No. 3 - Biscuits

Post by jsburger »

algale wrote: Mon Oct 18, 2021 7:11 pm
HopefulSSer wrote: Mon Oct 18, 2021 5:42 pm A week later he reconsiders his initial opinion somewhat:
https://woodworkingformeremortals.com/i ... i-thought/
Different guy.
I didn't pay any attention when I looked at the link. You are right it is not the same person.
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Re: Glue Myths No. 3 - Biscuits

Post by HopefulSSer »

Oops you're right. I had gone down a youtube rabbit hole and didn't pay close enough attention. Oh well, if you want to see this guy rag on biscuits, here you go! ;)
https://woodworkingformeremortals.com/i ... y-useless/
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Re: Glue Myths No. 3 - Biscuits

Post by RFGuy »

HopefulSSer wrote: Mon Oct 18, 2021 9:11 pm Oops you're right. I had gone down a youtube rabbit hole and didn't pay close enough attention. Oh well, if you want to see this guy rag on biscuits, here you go! ;)
https://woodworkingformeremortals.com/i ... y-useless/
It's okay. Those are interesting videos as well. Steve Ramsey puts out some good content, but he primarily focuses on the new woodworker and especially the very low cost woodworker. I think about the time those videos came out, there was a similar biscuit jointer video from Stumpy Nubbs, I believe. So, these videos were kind of playing off each other at the time they came out. I used to use biscuits for all of my panel glue-ups and I experienced some biscuits that would fit great and others that were very loose, so even the biscuits themselves vary...out of the same container! I remembered Steve commenting on his biscuit jointer making slots that were too loose which prompted him to buy the DeWalt and issue that rebuttal video. In my previous post where I referenced biscuit jointers having trouble creating the right width slot, it was partly a reference to Steve's video. It is worth pointing out that there is a high end biscuit jointer made by Lamello that costs like $1,500. I know at least a couple of production woodworkers, who happen to have YouTube channels, that use and love the Lamello biscuit jointer. Lamello even sells knockdown hardware that can be used in the biscuit slot. Check out Mike Farrington or Guy's Woodshop if you want to see a Lamello in action. In the end, it seems like all we get out of biscuit joints is the alignment of the panel during glue-up. Patrick Sullivan's new video (at top of this thread) seems to indicate that adding biscuit joints don't increase the strength of miter joints at least, but of course it keeps it from falling apart even though the joint failed. Lastly, these videos pointed out that Norm kind of kicked all of this off. Many woodworkers in that time period, myself included, watched Norm on The New Yankee Workshop and just had to buy a biscuit jointer because that is what Norm used. So, if you don't like biscuit joinery, blame Norm!!! ;) I still have my DeWalt biscuit jointer, but I don't use it anymore. Like I said the biscuits that I have used always varied quite a bit in thickness. In the last 1-2 years of using the Festool Domino I have been impressed that every Domino has a good fit, i.e. I don't see significant variation in thickness between them and they always have a good snug fit into the mortise. Not trying to sell anyone on the Domino, but just my experience. My biscuit jointer is forever retired now...
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