Official Luthiers Forum!

Thanks again to everyone who was able to join today's roundtable meeting. We had a new member, Craig Wilson, who joined. Craig is working on getting his OLF handle still. For now, he was able to join us at the meeting. We got updates from everyone on what they are working on, and we saw a number of ways to join plates! It's always interesting how many ways we skin the proverbial cat.

If you would like to submit anonymous feedback on topics, experience, etc... please fill out the form here - https://forms.office.com/r/HHEni87fAP

Highlights:

Intros:
Craig Wilson - 1:20
Bob Gramman - Impromptu demo of the spoon carver - 9:28 (Available here - https://www.woodcraft.com/products/carvers-spoon-plane)


What's on the bench:
Ken Nagy - 14:10
James Orr - 17:05 - Table saw conditioning with Carbon Method (Available here - https://carbonmethod.com/)
Bryan Bear - 18:50
Brent Tobin - 21:25
Kent Fishburn - 58:45 - Nice discussion on binding jigs!

Plate Joining Jigs
Bob Gramman - Using tape to clamp the joint with HHG - 24:05
Mike O'Melia - Spanish joint system using ropes - 35:35
Craig Wilson - Sergei de Jonge style wedge clamping system - 48:45
Brad Combs - Ukulele joining jig inspired by LMI commercial jig - 52:25
Don Parker - Wheel cam jig - 1:07:10

Demo - - HHG uses in guitar building. Great demo, Don! - 1:12:40
- Link to LMI's website to buy a glue pot before they run out (on sale for 70% off!!) - https://www.lmii.com/specialty-tools/29 ... e-pot.html
- Link to the silicone bands - https://bandjoes.com/
- Link to Urea on Homestead Finishing - https://homesteadfinishingproducts.com/ ... ents-misc/

Recording:
Direct Link - https://youtu.be/pFxZjjU5MCc

Embedded link:


Attendance report:
Craig Wilson
Bryan Bear
Mike O'Melia
James Orr
Brent Tobin (glad you're feeling better, Brent!)
Bob Gramman
Ken Nagy
Kent Fishburn
Don Parker
Brad Combs

Thanks to everyone who attended. Watch for the invite for next month.

Thanks all!
Brad

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Sorry I missed but had a guy come by to test out and pick up his guitar. Looking forward to viewing the video though

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Steve Smith
"Music is what feelings sound like"

As always, thanks for organizing this, Brad. I wanted to offer two clarifications regarding my answers to some questions during the Roundtable:

1. There are two different “waters” at issue, and I want to make sure there is no confusion. There is water that goes in the water bath, and there is water that gets soaked up by the dry glue to make the gel. I make glue by adding room temperature distilled water to the dry glue in the proportion we talked about, 1.6 parts water to 1.0 part dry glue, by weight. After that mixture gels (two minutes for the small amounts we discussed), I then heat it to 140F in the water bath. The water bath is created by putting hot tap water in the larger pot, then heating it on the hot plate. You put the smaller pot (which contains the gel) into the larger pot (which contains the hot tap water), which is sitting on the hot plate. Total time from dry glue to 140F hot hide glue is roughly 10 minutes, if you do things in the right order. I worried that this might have been slightly confusing, I hope this clarification helps.

2. When I said that you get a few minutes of open time with the addition of a small amount of urea, I want to offer a caution. This is all very imprecise, and subject to the conditions of your shop, the batch of glue, how much water you are using, etc. The salient point is that a small amount of urea will extend the pre-gel time, but not appreciably hurt the strength of the glue. I can’t say for sure you will get a specific amount of extra time. I’ve gotten plenty of extra pre-gel time from adding urea that amounts to 5% of the weight of the dry glue used to make the batch. By plenty, I mean enough to glue on a top or back without moving like a whirling dervish. If something is going to take a lot longer (like when I build purflings), I just add enough urea to make the glue liquid at room temperature (the urea is 20% of the weight of the dry glue for this), and limit its use to decorative elements.

I hope those clarifications are helpful.

Thanks Don, I didnmt mean to try to pin you down to an actual time when I asked about added open time from 5% urea. Obviously there are many factors that would affect the actual open time. I didnmt ask the question well, I was looking to find out if the increase was fairly significant with such little idea. Your answer was what I was looking for, but it is good that you offered your clarification here. . .

Thanks again Brad!

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Your question was fine, Bryan, and no worries. I answered it without qualifying, so I wanted to do that here. I would hate for someone to go use urea, have a glue failure, and think that I led them astray. I know you wouldn't be one of those folks, but the video is for general OLF consumption, so I thought I should add some caution.

Sounds like a good session once again, I’ll check out the recording. One day I look forward to joining you all but this time yet again I failed to drag myself out of bed at 4am


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I just ordered the glue pot, and warmer. I've seen that one, or something very similar advertised, and recommended YEARS ago, and other times since then, and opted for cheaper options that never did satisfy. Interesting statement. Anyway; for $60 for the two of them, I can't go wrong. The pot alone was about $100 maybe 20 years ago when I started.

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Why be normal?

Ken--

Just one thing about the coffee cup warmer that LMI sells: It will probably do a good job of keeping the glue pot warm, but the process of getting the glue pot up to the right temperature in the first place might require something with more oomph, like a hot plate. Obviously, experiment to see what works for you. I'm impatient, so I use the laboratory hot plate I showed in the demo.

Don;
My hot water is HOT.

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Why be normal?

Oak always surprises me. I just don't think of it as tone wood at all!

Stunning.

wrong post!

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Why be normal?

No running water in my shop. I bought a cheap microwave and use that to heat the water for my glue pot. Helps speed things up a lot.

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Steve Smith
"Music is what feelings sound like"

Fantastic info and demos as always. Very valuable.
Thanks for putting these together Brad!

Don, quick follow up question. You mentioned 5% urea by weight but I did my ask if you meant 5% of the weight of the dry glue or 5% of the total weight (glue and water).

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Bryan—

When I use urea, I compare the amount of urea to the amount of dry glue I used to make the batch. So, when I say 5%, I mean 5% of the dry glue only and ignore how much water I add to the mixture.

I figure it wouldn’t hurt to mention a few other details of how I make a small bit of glue, with or without urea, just in case anyone has purchased the Hank Levin glue pot and is curious. When I mention in the demo the order in which I do things, it goes like this:

I turn on the hot plate. I go to the sink with the glue pot and fill up the exterior glue pot with hot tap water. I displace the excess water by sticking the interior pot into the exterior pot over the sink. Then I pour just a bit more water out. That gives me the right amount of hot bath water. I put the exterior pot on the hot plate. I put the interior pot into the little wooden pot holder, without the lid, and put the interior pot with holder on the scale, and zero the scale. I measure in how much dry glue I want to use. I then measure in the amount of distilled water I want to use. Note that the distilled water is room temperature, not heated. Then I leave that for a few minutes, which is all it takes for the dry glue to soak up the distilled water. Once it is soaked up, I put the interior pot into the exterior pot, with the lid on, and let it heat up. I stir every minute or so. In a few minutes, the glue is fully liquid and ready to use.

If I am going to add urea, I put a plastic cup onto the scale, zero the scale, and measure into the cup the amount of urea I want to add to the glue. I do this while the glue is heating up. Once the glue is hot, I dump into the interior pot the urea pellets, and put the lid back on. I check that every minute or so, and stir it. If there are still white pellets when I stir, I give it another minute. When the pellets are gone, the urea has dissolved into the glue. A good stir again, and it is ready to use.

Hey Don,

I didn't get a chance to attend or watch the video so please excuse my ignorance if you covered this already. I've just completed a pair of guitars mainly utilizing HHG and had heard about small amounts of urea being added. Thanks for the more concise recipe. Just one silly question from me--where does one find urea commercially?

TIA

Hey Doc, there is a link at the top to Jeff Jewitt’s company, Homestead Finishing. Scroll down about halfway.


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Howard--

Brad's right; buying from Jeff Jewitt is a good way to go. Another way to buy it is to just look for urea on Amazon or eBay. It is a common fertilizer product. You want the 46-0-0 type that comes in pellets (also known as prills). They are small white balls, about the size of a BB or smaller. But I can 100% endorse buying from Jeff Jewitt at Homestead Finishing. Same stuff.

Very informative session. Thanks to everyone for sharing.

Just want to say how enjoyable and informative the the meets have been. I watched them all. Hope to participate in one when I learn about zoom and maybe sweep (or shovel) off the bench.

Thanks to all contributors! Great stuff.

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Brian R, Wood Mechanic
N8ZED

Brian—

If you ever want to take a few minutes and practice with a Zoom meeting, let me know via a PM here on the forum. I have a corporate account, and would be glad to host one with just you and me participating. You need an e-mail address and a device (computer, iPad, iPhone, whatever) that has a camera and a microphone, although in a pinch you can just call in on a phone and participate by audio only. Frankly, I’m impressed that you have made it through the last 3 years without being forced to use Zoom!