Minerva Monitor: "Patience my ass, I'm going to go build something!"

[ColoradoTom]

Yeah, but maybe that should be "Patience my ass, I'm going to go test glue something!"

A colleague of mine that I helped hire, who is Danish (but I don't hold it against him... ;-) and I have a favorite motto which drives some of our colleagues in Europe and the Far east a little over the edge...



Of course, there are variations of that, such as



But we don't need to go there...

OTOH, when I do get out to the shed sometime in the near future, I will use the Gorilla glue as the test adhesive. BTW, tried to buy Titegond Polyurethane glue locally, no joy- and going on Amazon, they had the curious item in the product detail that that it was discontinued by the manufacturer- might have just been that particular container size or something...

Until we do our own testing, I'd say TP Urethane glue is off the table for now. I'll order one bottle from Amazon and do some tests here. If you feel like also following up on that and sharing your thoughts, it would be fine and appreciated.

Hi Guys....

Haven't been active for a while but here's my feedback:

I use Weldwood® Plastic Resin Glue (urea formaldehyde) on all my glue/lamination work that requires longer open time and where I want to make sure there will be no creep or to minimize spring back in bent lamination. I also use it on the majority of my veneer work - it works great in a vacuum bag. It does require my shop to be over 65 degrees, requires mixing, and you need to wear gloves.

I use epoxy for all "oily" wood glue up (rosewoods, teak, Ipe, ect.). I've been making furniture out of Ipe and actually use an epoxy that is specially made for it that works better than anything else I've tried.

Everything else I use the various titebonds.

I don't like polyurethane glue at all.... several bad experiences with it.

Tom

PS - Jon has a saying that "if too much is OK, more is better" - I needed to build something audio related and decided to use 4 Dayton UM18-22 Ultimax 18" subs in 4 parts express 4.0 cu ft enclosures. Haven't made measurements yet, but did find out that I have a nasty resonance at around 18 Hz that I never knew about before. My wife hates them because they shake everything in the house even on the second floor (I'm in the basement)!!!

[JonMarsh]

The full version of that saying is "If some's good, more is better, and too much is just enough". Mmm, 4 UM18-22 might come under the heading of "just enough". :W :T

Thanks for the glue feedback- especially valued from someone as experienced as you are. :T Something else to add to my test list. Ordered this AM. I'm normally a West Systems Epoxy fan these days... but we're looking for something a little less over the top.

[5th element]

Amazing work as usual Steve!

[Steve Manning]

Thanks 5th .....

[Steve Manning]

Hi Guys....

Haven't been active for a while but here's my feedback:

I use Weldwood® Plastic Resin Glue (urea formaldehyde) on all my glue/lamination work that requires longer open time and where I want to make sure there will be no creep or to minimize spring back in bent lamination. I also use it on the majority of my veneer work - it works great in a vacuum bag. It does require my shop to be over 65 degrees, requires mixing, and you need to wear gloves.

I use epoxy for all "oily" wood glue up (rosewoods, teak, Ipe, ect.). I've been making furniture out of Ipe and actually use an epoxy that is specially made for it that works better than anything else I've tried.

Everything else I use the various titebonds.

I don't like polyurethane glue at all.... several bad experiences with it.

Tom

PS - Jon has a saying that "if too much is OK, more is better" - I needed to build something audio related and decided to use 4 Dayton UM18-22 Ultimax 18" subs in 4 parts express 4.0 cu ft enclosures. Haven't made measurements yet, but did find out that I have a nasty resonance at around 18 Hz that I never knew about before. My wife hates them because they shake everything in the house even on the second floor (I'm in the basement)!!!

Hey Tom ........ what were your issues with the polyurethane glue out of curiosity?

[sdl2112]

Steve, Yes...there's nothing better then experimenting up front to avoid issues later to give you confidence in the process. As Jon said those look too good for destructive testing

I'm in the process of working with LBL and I should mention I do have some concern with the LBL translam, that is relying on the inner layers for strength perpendicular to the grain. Where the cross-laminated LBL provides maximum strength in all axes by placing the fibers in tension or compression parallel to the grain. The translam only provides this in two axes, the other axis is subject to pulling the grain apart like splitting firewood. I don't know if the inner layers are a lower grade bamboo but I have seen hairline fractures and voids a few times...just something to watch out for.

Also out of curiosity...wondering which you will choose...you have two options to orient the grain, say for the front you could have the inner LBL bamboo layer grain oriented vertically, outer layers horizontal or vise-versa. Both looking interesting.

Keep up the great work :T

[ColoradoTom]

Hey Tom ........ what were your issues with the polyurethane glue out of curiosity?

About the only thing I can think of where they might have an advantage over another option is gluing metal to wood, otherwise:

Gap filling properties suck - it basically fills the gap with foam with absolutely no shear strength.
F*cking messy - I hated it.
Sucks at controlling spring back on bent lamination work.
F*cking messy
Limited shelf life once it's opened.
Can't control open time like you can with epoxy
Did I mention it's F*UCKING messy.

In my mind epoxy is always a better alternative - the only downside is it requires mixing. My outlook is if you can't spend the time it takes to mix epoxy, then go right ahead and enjoy the convenience of polyurethane, but for my projects the extra 15 minutes to use epoxy is a no-brainer.

[JonMarsh]

Your objection #1 is something I've heard frequently from others on woodworking forums; which was why I posted the two forum quotes earlier in this thread.

Thanks for the feedback and for chiming in on this, Tom.

[ColoradoTom]

Hope I didn't sound condescending...

I did think of one possibility where it might be used and that is where the materials you're using are wet/damp (since moisture helps the bond). I can't imagine any case where that would be true with anyone on this site, unless they were building their speakers outdoors in a rain forest - and glue would probably be the least of their problems8O[



BTW - I know if there aren't pictures it doesn't exist.

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[dar47]

Haha, Tom a man after my own heart but in a strictly when it comes to glues. 8O

Got some Weldbond (plastic wonder glue)on maple under clamp and we will see! What are those speaks, beautiful?

[ColoradoTom]

Plastic Resin Glue (urea formaldehyde) is great stuff and I'm pretty sure you'll like it... if I am doing any lamination work it's my first choice. I built a bed for my daughter using a large bent lamination for the support out of cherry that I ripped into thin pieces and laminated with Weldwood® Plastic Resin Glue and it's held up for nearly ten years under significant stress without any problems at all and the 20 glue lines in the laminated pieces are nearly invisible!

Speakers are Soundlab M-1 electrostatics with updated panels and transformers. http://www.soundlab-speakers.com/millenium-series.html

My DIY speakers are in the home theater keeping my 8 Aurasound subs happy!!

[JonMarsh]

Gosh, Tom, that Strat looks a little lonely over there in the corner- what do you plug it into these days? :W

[TEK]

...
I built a bed for my daughter using a large bent lamination for the support out of cherry that I rip
...
My DIY speakers are in the home theater keeping my 8 Aurasound subs happy!!

Yhea, sure... as if any of that actually exists;-)

[JonMarsh]

Yhea, sure... as if any of that actually exists;-)

Colorado Tom is a wood worker of some renown, in my book. Somewhere we have posts of his DIY speakers, ahem, at least the ones I'm familiar with will be a familiar design to some on the forum. (For those who know what an M8ta is... He has one of the more "upgraded" versions that were developed (you might think of it as a two way ancestor/father to the Ardent). I'll see if I can't locate the posts and pics. I've got some pics of some of his home furniture projects; if I could afford to hire someone to build furniture for me, as opposed to just speakers, Tom would be it. Of course, I can't imagine being able to afford Tom!

Mind you, pictures can be faked, and I've seen his setup and speakers in person, so unless I was brainwashed at the time... (Evil Twin? Force mind push?) I think they're pretty real... :W

[ColoradoTom]

Gosh, Tom, that Strat looks a little lonely over there in the corner- what do you plug it into these days? :W

The Strat is anything but lonley!!




I'm plugging it into the Peavey Classic 30 EL-84 based tube amp seen in the second picture. I can do a pretty good imitation of early Paul McCartney's sound thru it when I jammin' on the Hofner bass! 8)

[ColoradoTom]

Yhea, sure... as if any of that actually exists;-)

Well.... since the gauntlet has been thrown down:

Home theater with Geddes Abbey12 and four of the Aurasound subs:



Close up of the Abbey 12 with curved laminated 1.5 inch thick sides (alternating 1/8 inch high density mdf, 1/8 inch plywood, and finally 1/8 inch re-sawed cherry):



My daughters bed:



Close up of arch which is 2.5 x 5.5 inches consisting of 20 1/8 inch re-sawed cherry pieces:

[ColoradoTom]

Colorado Tom is a wood worker of some renown, in my book. Somewhere we have posts of his DIY speakers, ahem, at least the ones I'm familiar with will be a familiar design to some on the forum. (For those who know what an M8ta is... He has one of the more "upgraded" versions that were developed (you might think of it as a two way ancestor/father to the Ardent). I'll see if I can't locate the posts and pics. I've got some pics of some of his home furniture projects; if I could afford to hire someone to build furniture for me, as opposed to just speakers, Tom would be it. Of course, I can't imagine being able to afford Tom!

Mind you, pictures can be faked, and I've seen his setup and speakers in person, so unless I was brainwashed at the time... (Evil Twin? Force mind push?) I think they're pretty real... :W

I'm currently building an entertainment center and kitchen table for neighbors..... I only charge for materials and ask for a donation of a REALLY good bottle of single malt scotch!!

:W

Gave the M8ta's to a friend that was going thru a really bad time.

[JonMarsh]

Yeah, I remember now you talking about your Geddes build- turned out very nice. Hope your friend is doing better these days- and thanks for sharing the pictures! :T

Of course, this leaves open the question of just what is a REALLY good bottle of single malt scotch?

Something like this?

[TEK]

Colorado Tom is a wood worker of some renown, in my book.

Jon, Colorado Tom throw the glowes first with his own comment:

BTW - I know if there aren't pictures it doesn't exist.

I just picked it up and slapped him a bit with it :lol:

But boy, did he take that challange ;x(
Colorado Tom: really great work - both on the speaker finish as well as the rest.
I'm especially impressed by the combination of design and craftsmanship on the bed. A lovely furniture that is!

[ColoradoTom]

Thanks TEK......... My job drives me crazy, woodworking keeps me sane!!

[Steve Manning]

Very nice work there Tom and thanks for the input on the glues.

[Steve Manning]

Abuse Time

Time to see how the glue holds up .......

Implements of abuse ....... 3 lb hammer and cold chisel :twisted:



First up was the glued on both sides parts ....... stood parts on block of wood so as to catch only one of the two pieces. Hammered the other piece. Boards took some damage, not much else.





Next I set the chisel on the glue joint and tried to separate the pieces. Wood cracked elsewhere and joint remained intact.

[Steve Manning]

Second part up ..... one has glue on one surface of the joint.

Hammer up ...... Board did not like the hammer, glue joint held fine.



Chisel on joint and the board split to the left, glue joint still happy.




Conclusions? Is it the best choice of glue? Seems to hold up, at least in the short term, in this type of application, pretty well.

[JonMarsh]

TB? Hard to argue with the results you're getting... Steve, it must be something about your technique! :B How to explain other comments I see?

[Steve Manning]

That I do not know ..... The guys at Woodcraft agreed with what Tom suggested, urea formaldehyde is the way to go for laminating, with the caveats of being very messy and it needs to be done in a warm space. Next best was this stuff. It is designed in particular for laminating boards, or other materials, together and then clamped, as in, no voids between pieces. As such it's not meant to fill voids, which Tom has also noted, it does not do well. It is a bit on the messy side itself, but if you go into things knowing that and are prepared, no big deal. Scrapping off dry squeeze out was a breeze. I did see in the instructions about spraying surfaces with water for nonporous materials or dry wood to aid in curing since moisture is required for it to cure properly. The parts also have to be clamped together. It could be that spritzing the lbl with water might be a good idea since it is rather dense?

[Steve Manning]

Steve, Yes...there's nothing better then experimenting up front to avoid issues later to give you confidence in the process. As Jon said those look too good for destructive testing

I'm in the process of working with LBL and I should mention I do have some concern with the LBL translam, that is relying on the inner layers for strength perpendicular to the grain. Where the cross-laminated LBL provides maximum strength in all axes by placing the fibers in tension or compression parallel to the grain. The translam only provides this in two axes, the other axis is subject to pulling the grain apart like splitting firewood. I don't know if the inner layers are a lower grade bamboo but I have seen hairline fractures and voids a few times...just something to watch out for.

Also out of curiosity...wondering which you will choose...you have two options to orient the grain, say for the front you could have the inner LBL bamboo layer grain oriented vertically, outer layers horizontal or vise-versa. Both looking interesting.

Keep up the great work :T

Interesting Scott ...... If I'm following you, hopefully the dowels running through the cabinet will help with additional strengthening as well as alignment?

[TEK]

Interesting Scott ...... If I'm following you, hopefully the dowels running through the cabinet will help with additional strengthening as well as alignment?

What dowels are you talking about here? It's just wood on wood, right?
Some of the translam project I have seen fail has been (they believe at least) caused by metal rods trough the translam. And when the wood expands or compresses and the metal rod does not, that causes the wood to break.

Wood-on-wood should not give such a result (I think).

[ColoradoTom]

I would agree with the suggestion to moisten the wood - especially if its dense or you live in a dry climate like the south western US, it does make a difference in the cure of poly glues. One of the reasons I like urea and epoxy is that I can dye urea with water soluble dye and i can add sawdust to epoxy to match the color of the object I'm building - neither of these is probably important to anyone here though! :W

[Steve Manning]

What dowels are you talking about here? It's just wood on wood, right?
Some of the translam project I have seen fail has been (they believe at least) caused by metal rods trough the translam. And when the wood expands or compresses and the metal rod does not, that causes the wood to break.

Wood-on-wood should not give such a result (I think).

TEK, if you look back at some of the earlier pictures in the thread, a lot of the holes you see are for alignment dowels, which in this case are planned as wood.

[Steve Manning]

I would agree with the suggestion to moisten the wood - especially if its dense or you live in a dry climate like the south western US, it does make a difference in the cure of poly glues. One of the reasons I like urea and epoxy is that I can dye urea with water soluble dye and i can add sawdust to epoxy to match the color of the object I'm building - neither of these is probably important to anyone here though! :W

This time of year in Virginia it's usually on the dry side, summer, rather swampy. I've started spraying some water on projects for grain raising prior to finishing as well. Good idea on the coloring of the urea with dye.

[dar47]

Great you guys are happy with your Glue. I just wanted to see how this stuff performed.

Well like the movie Iron man when Tony says " Your still taking me to school 30 years later" my old man loved Weldbond.

Made a cherry hammer to test Weldbond note this is a 15 year old bottle that says it's good for 5 years. The glue was added just at the end and only one clamp to simulate a poor glue joint. Glue on a dense wood doesn't absorb into the wood fibers like plywood so it's shearing strength is jut it's surface grab. Here is the cherry hammer.

Image not available

Hammered it twice full swing on edge of my bottom 3 point tractor hitch lower arm to see if it would pop it. no go. Then tried to shear it with prying almost full weight (I didn't want to fall over into the hitch though.) no go. notice hammer and wedge marks.

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I then turned 90 degrees and pushed which got the glue to start snapping apart. Was the wood going to tear not likely it would snap the wood first with my test. When separated you could see poor clamping which started the glue failure. I would have no problem trusting this stuff as it is as least as good as epoxy and better then Tight Bond 1, 2 or 3. Easy to apply no mess. The wonders of Plastic glue. Not sure you can see the glue failure but the lack of clamp aided in it's failure.

Image not available

[ColoradoTom]

Yeah, I remember now you talking about your Geddes build- turned out very nice. Hope your friend is doing better these days- and thanks for sharing the pictures! :T

Of course, this leaves open the question of just what is a REALLY good bottle of single malt scotch?

Something like this?

Well, this stuff was given to me and it's pretty good!!

[sdl2112]

Interesting Scott ...... If I'm following you, hopefully the dowels running through the cabinet will help with additional strengthening as well as alignment?

Steve...I don't think I'm telling you anything you don't already know but with the translam you are relying on the strength of the inner layers perpendicular to the grain. This will not be as strong as parallel to the grain. The dowels should help. Btw...are these dowel segments connecting two pieces at a time or a longer dowel connecting the complete width?...I would think the segments would work better as a long dowel may have different expansion properties to that of the bamboo causing stress.

Anyway below I show the LBL and and translam segment. Forces in the direction of the arrows or bending along the length would break the translam piece sooner as I showed earlier. Now with your build there shouldn't be forces in those directions. I think most glues discussed should work well....I just have a small concern for some of the internal irregularities I have seen. The next two photos show internal hairline cracks and where the outer layers are not glued too well. Now I don't see too much of this but it is something to watch out for.


Hairline crack


Bad glue joint

[JonMarsh]

Thanks for your observations. Very rarely have I seen defects like you've pointed out, and I have been looking...

My test this weekend should be more like DAR47's; I have both the TB Urethane glue and the Gorilla glue, now I'm looking to acquire some Weldbond, though that will likely have to be ordered online, too.

[JonMarsh]

Ordered the Weldbond yesterday, it's here today... any faster and I would have gotten it before I ordered it!

Maybe it was the Spin Doctors CD I ordered at the same time, created a distortion in the space time continuum... I hear their old hit (Two Princes) on the radio around here and figured I needed to have that on the CD to see what it sounds like on the Minerva's cranked up...

[ergo]

Doing some progress also... getting there with my alternate CNC box style.

I'll use more planar pieces all in all and will put a 2mm bitumen damping sheet between all planar outer walls. I've had this idea for a while and I think this is the time to try it.
I did use a bitumen sandwich on my Modula MKII clones but only between double front panel.

Also thinking about "decoupling the outer front panel planar pieces" by cutting those with some 3mm offset to inside. Then each of those panels would connect to rest of box only via bitumen. Filling the 3mm side gap is a bit of question then. Possibly filling with silicone type material would be ok as it will be elastic. Especially for the coax unit this would perhaps isolate it from woofer's mechanical action.

With current go I'm getting by with bit more than 10x 600x800mm LBL sheets (but I do have 2 400x800 sheets already).

[JonMarsh]

Looking very nice, Ergo! :T

Steve had a productive update from our vendor for the CNC work, after Stever completely reworked the drawings and updated the curve/circle segment density substantially- more on that later today when I'm at home or if Steve chimes in. Getting things sorted with this vendor has been more of a challenge than expected- I think if we walked in with something as intricate as your current plan, the guy might flip out, considering the issues we've had with our "simple" version.

We've got some mild weather and I'm seriously hoping to get some time in the Storage Shed workshop today; I've got to get those together sometime, and I'd rather it was before we get the translam version assembled! Otherwise, so embarrassing!

OTOH, there's been a lot on the plate on various fronts, work related and otherwise, including helping my GF get some technical things sorted out for her upcoming trip to New Zealand (this is one I'm really sorry I'm missing and couldn't get the time off from work). (A gal she met on our Antarctica trip and hit it off with is on this one, too, so that's a big plus).

[Steve Manning]

Chiming in a little ....... just got back from the lumber yard with round two of test cuts (I'll get some pictures a little later), much better results than round one. As Jon noted I had to up the resolution for all the arc's in the drawings, considerably. With Sketchup, what looks good in a drawing does not always translate to good machining. In Sketchup circles are are a series of line segments, the higher the number of segments the smoother the arc. I upped the number of segments in a circle from 48, which looks reasonable in a drawing, but not when you machine it, to 360, which gave much better results.

Ergo ... looks like your having fun. Jon's right, the guy I'm using would a small conniption seeing your drawing. We sat down for 2 1/2 hrs this week going through files to get everything laid out as needed just with what I designed.

[JonMarsh]

Test cuts from our vendor- these are with the re-done drawings Steve prepared recently, and to his eye, it looks like they'll get the job done OK. (mine, too! :T )

Main cabinet pieces...




Outside piece on stand pillar...




Stand pillar sandwich showing cable path...



Needless to say, this is all fairly encouraging to me- looks like Steve has got things sorted out well with the vendor. At this juncture, it looks ready for the production cuts, after Steve inspects in person.

[dar47]

Lessons learned, we started with solid works, Industrial grade and the guy running the tool path made the drawing to adjust as we went along. I see now how this was well worth us doing the whole process. Keep plugging guys it's going to be great when you finally have parts in hand!

[ergo]

I can very well imagine the process from Sketchup to CAM. Been there done that too.
Sketchup is real good for concept drawings and architecture stuff, but not really for getting stuff machined later on.
This is largely the reason I got an educational version of Rhino 5 as that's really a full 2D/3D CAD that can do modelling. It is much easier to export from Rhino to CAM like Vectric ones as all arcs and circles are truly that etc.

This is what my wife can do for house modelling We are planning the terraces / outdoor kitchen area in back garden and this is the concept we have. With snow on ground now is a good time to plan ahead

[Steve Manning]

Actually going from Sketchup to Aspire has not been too bad. It appears that with the popularity of Sketchup on the rise, especially in the woodworking world, CAM integration is becoming better. The obvious appeal of Sketchup, as it was for me, is that it's free :T and it's rather easy to learn how to use. I'd rather spend the money on material and drivers than a grand or two on a software package.

[ergo]

Steve / Jon

I see that on your plans you have a gap between side panel and main box frame. The 3D render has a shiny aluminium like look there. Do you have a plan to cut a layer of aluminium there?
If so, that would sure look very nice indeed.

I've tried to cut aluminium on my machine - that's even a bigger challenge than any of the woods. But I guess as anything it's down to experience and knowing bits/feeds/speeds again.

[Steve Manning]

Yep, that's aluminum, though not a solid sheet. Even though that would be the easiest approach, the cost for solid 1/4" thick aluminum sheet, that size and quantity, even without machining costs being added, gets pricey in a hurry. So it will be 1/4" square material made into a ring.

[JonMarsh]

I can very well imagine the process from Sketchup to CAM. Been there done that too.
Sketchup is real good for concept drawings and architecture stuff, but not really for getting stuff machined later on.
This is largely the reason I got an educational version of Rhino 5 as that's really a full 2D/3D CAD that can do modelling. It is much easier to export from Rhino to CAM like Vectric ones as all arcs and circles are truly that etc.

This is what my wife can do for house modelling We are planning the terraces / outdoor kitchen area in back garden and this is the concept we have. With snow on ground now is a good time to plan ahead

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Looks great, Ergo! You've got some nice plans, there... we'll all be curious to see how they're realized, and wish you the best of luck in getting things to turn out the way you want! talented wife, too, obviously! :T