Well, plastic resin glue is not the answer.
Building a shower dressing bench from ipe. 3/4 x 1 1/2 slats with 3/4″ x 1 1/2 x 1 1/2 spacers at the ends, bench is 37″ wide and about 18″ deep to be supported at the ends on 1 1/2 x 1 1/2 stainless steel angles secured to the walls of the alcove where the bench is installed.
First attempt with the plastic resin I failed to keep everything at or above 70 degrees as called for on the packaging. The thing fell apart. Sanded all the mating surfaces back to virgin wood, heated everything up to about 75 degrees and maintained 75 – 80 degree temps for a 24 hour cure period.
Removed clamps in the shop and brought the assembled bench into the house for final 7 day curing. The change in environmental conditions caused just enough movement in the material to essentially destroy every glued joint. I could literally break the pieces apart with my bare hands. Plastic resin glue may be totally waterproof but it’s unforgiving in its brittleness.
Next step is West Systems epoxy.
I no longer have much faith in any kind of adhesive being able to bond this stuff so I intend on putting a piece of 1/2″ allthread and chrome acorn nuts and washers at each end to provide a more positive mechanical “bond”.
No question here, just reporting the results of the process.
Replies
I never had any problems using polyurethane glue. And I've done a fair bit of teak and ipe work (ipe is 1/3 the price of Teak here).
Fairly freshly jointed edges, a wipe with water on the one board, and a nice coat or bead bead of glue on the other. Keep it clamped for 6-8 hours, and enjoy.
The older I get, the better I was....
Probably a dumb question but does sanding qualify for "freshly jointed"? The reason for asking is this will be the third attempt at gluing this thing up. Any machine work will begin to affect the dimensions of the finished piece!
Thanks for the input.
Dennis,
Sanding a surface to be glued is not a good idea. "Jointing" means just that, preparing a suface for a glue joint. A hand plane makes the best surface as the iron cleanly cuts the tissue. A jointer is a close second, and is, of course the most used method of preparing wood for a glue joint. Sanding leaves the fibers rough and torn compared to the slicing action of a blade. The torn fibers are a poor substrate for glue adhesion.
I agree with the previous post. I have had excellent results with polyurethane glue applied exactly as described.
Rich
OK - thanks, Rich. I'll certainly take your advice. Third time's a charm my Mom always used to say.
>> Sanding leaves the fibers rough and torn compared to the slicing action of a blade. The torn fibers are a poor substrate for glue adhesion.
With due respect, I'm not sure I agree with this. The glue will find its way behind the "rough and torn" fibers onto more solid "substrate". that's why one uses clamps to assemble the glued parts.
A more important reason for jointing (cutting) vs sanding is you end up with a flat edge & square corners, a requisite for a sharper, less visible glue line, if you care about such things. With sanding, you run the risk of rounding off the edge and the corners, with results that are less than ideal.
Nope, tests clearly show that glue adheres better to a surface prepared with a sharp cutting edge than to the torn surface left by sanding.Rich
Not to be too argumentative, but planes and scrapers shear wood fibres with one cutting edge. Sanders cut wood fibres with numerous cutting edges, with differing heights and degrees of sharpness.
The issue is more along the lines that sanding tends to burnish and close the surface pores, as well as fill/pack them with fine dust, whereas planing opens the pores and doesn't muddy the graining.
For a weak analogy, try cutting drinking straws with scissors or shears, then try sanding the ends.
But- it is the sanding effect that is precisely what is needed to minimise the differences between face grain and end grain, and to reduce blotch on certain woods.The older I get, the better I was....
Another problem with sanding is that it can round edges a bit, clearly a bad idea in a glued joint. Without addressing the question of whether planing would be superior, there are times when sanding is clearly helpful. When gluing oily wood, washing with acetone is frequently suggested. There was a brief test a while back in FWW, where an oily wood was glued up after no treatment, acetone wash, or light sanding, and then the breaking strength of the joint was measured. Acetone helped a little, but much less than did sanding. The interpretation was that the fresh surface was important, not the sanding per se. But the strongest bond to oily wood resulted from gluing with epoxy rather than yellow glue. This was not an extensive test: it did not compare other surface prep methods, glues, types of wood, joint durability, effect of moisture cycling, or any of the other things you might ask.
Edited 12/15/2005 12:03 pm by AlanWS
I read that article, and I believe there was also some question as to whether wiping with acetone caused the migration of oils to increase.
Nonetheless:
1- Joint edges.
2- within an hour wipe one side with damp rag, apply Polyurethane glue to other side.
3- clamp for 6 - 18 hrs - but not deathly tight..
4- use scraper to remove excess glue. and enjoy benefits of wider board.
Never had an ipe or teak edge joint fail using the above method. And believe me- there would have been phonecalls.....The older I get, the better I was....
Alan,
I've glued lots of tropical (oily) woods. I always wipe with acetone just before gluing, and I've been using polyurethane glue (Gorilla) with excellent results. There are epoxies that may be better.
I cannot attest to the acetone wipe as imparting any better glue bond, I just do it out of habit. But here is the part that I and others have tested, and which is known to be the simple truth.
The joint surface should be prepared as close as possible to glue-up. The longer the time between preaparation and gluing, the weaker the joint.
For oily woods, even a few hours will make a difference, as the freshly-prepared surface is as oil-free as it will ever be. With other woods, oxidation of the fresh surface impairs glue adhesion. Twenty four hours can make a difference regarding oxidation for all woods.
This means, for the best glue adhesion, boards should be jointed immediately before glue-up, or a final, very light pass with the jointer or plane should immediately preceed glue up for boards that have been jointed hours or days earlier.
I have used yellow wood glue on oily woods with very good results, but I prefer polyurethane, as acetone clean up, before it has set is so easy and complete, leaving the wood suface absolutely clean and unstained with no raised fibers. Such complete clean-up is not possible with yellow glue and further surface work is always necessary.
Rich
Plastic resin glue is not waterproof, it's water resistant. It also has to be fresh and mixed correctly. The threaded rod is the only sensible way to keep the bench together. Ipe likes to move and the face grain to face grain alignment will likely fail with just glue. West systems epoxy is very expensive and sometimes requires a filler. Titebond 3 is a good waterproof glue but PL premium in a tube would be my choice in a shower with ipe. Just don't expect any glue to do the job alone. You can countersink the nuts and cap them with a plug if you don't want hardware showing.
Beat it to fit / Paint it to match
Hi Hammer -This "shower bench" isn't really in the shower proper. It's a dressing bench just outside the shower proper where it won't get inundated constantly with shower spray.The biggest problem with the plastic resin is that it's just so dang brittle and hard when its cured out. I think that, because of the movement of the ipe is what caused the piece to literally fall apart. I've had reasonably good luck with it in gluing other species, though. And yes, a mechanical method is indeed the only practical solution given the limited amount of surface(s) being glued in this situation.Thanks for your comments and encouragement.
I am very sorry to hear your frustration. Remember this is a learning process for all of us. I agree with the others. I have made outdoor kitchens/ cabinets using Ipe. I used Titebond 2, those were before Titebond three was availible. No failures after a Texas year. I have also used Poly. It seemed to work better when I've used it on exterior trim work (mostly Cyprus and ceadar) but the foam out and sticky mess was too much trouble for me. Unless the work will be submerged exotic adhesives seem to be unnessary. I suspect that your problems stem from not rejointing everything. Also a lot of those epoxies and plastic resin glues need less clamp pressure so the joint isn't glue starved.
Keep your chin up,
Mike
Hey MudMan -Thanks for the reply.I've about given up on trying to bond ipe with any kind of adhesive. As you say, TiteBond may work OK but I'll stick to mechanical fastening for the few simple projects I have in mind for the stuff.I say this because today I was building a towel shelf to go in the shower (over the infamous dressing bench that started all this) and needed to do some light sanding to remove some router bit machine marks. (Why ipe for a towel shelf? - so it will match the bench is simply all there is to that). Anyway, sanding this stuff it's immediately apparent that it's absolutely LOADed with oil. The sandpaper gums up in but a few strokes! Plastic resin glue is, I'm finding out, simply far too brittle to bond much of anything where there's going to be any significant movement. Haven't tried epoxy but I suspect without the 'fresh machining' operation it would have a hard time sticking. For the bench proper I think I'll go with the poly glue with a quick acetone wipe just prior to glue up. But for a keeper I'm running a 5/8" allthread through both ends so there won't actually be any total reliance on a glue bond to hold these pieces together.What's making this an interesting project is trying to find a way to have a finished appearance on the face of it what with the all thread running through. Considered chrome acorn nuts but 1)way spendy and 2) not available immediately locally. Regular steel or even cad plated fasteners are not an option - don't want any potential for rust here.Just happened to have a nice long piece of 1" diameter SS bar stock so decided to drill & tap 5/8 x 11 thread in the end of a short (3/4") piece and make a 'round' nut that could be counterbored into the face of the bench. I think the design time associated with this silly project has exceeded the actual production time several times over. And it's still not done yet.But I'm having so, so much fun!!
Most Lowes stores have a full selection of SS hardware. I know that they have acorn nuts, and they are not expensive maybe 1$. The allthread will rust bigtime unless it is SS or brass. I've not seen SS all thread, but it must exist. I have seen brass all thread. Could you make a purlin or batten that dovetails into the underside? That will mechanicaly hold it togather and allow movement. Through bolting a panel will almost certiantly cause problems during the expansion cycles. Either the hardware will fail (don't underestimate the force generated) or the boards will be deformed during a expansion cycle and then there will be gaps when it contracts.
Are you certain that the lumber is dry? A lot of South American lumber is not well dried. I hope I'm not sounding like I am poo-pooing your ideas, just hopeing to help prevent more headaches. Are you married? Heh heh, if so I can imagine what your wife is thinking.
Mike
Actually, Mike, I was lucky to find someone in our local Lowe's that even knew what an acorn nut is let alone find one. And no, they didn't have any, chrome, SS, zinc plated or otherwise. I've since come up with the idea of machining my own little threaded disc affair that will present a finished appearance at the face. The allthread won't be subject to water as in a bench that's actually <in> the shower per se plus it will be burried inside the wood.Yes, I'm aware of the expansion/contraction issues of trying to hold several pieces of wood together with a threaded rod. In my earlier life I thought I'd be cute and hold a bench top together this way, one made of ordinary 2 x 4's on edge. Several up to 1/8" gaps in the top later I learned what expansion/contraction was all about.Not sure as to how dry this ipe stuff is. I finished up the towel shelf today that has a lap joint at the corners that I glued with Gorilla Glue. Did the acetone wipe and dampen one side/glue to the other - left in the clamps three hours and it's holding quite well. I think if the bench assembly holds together this well I'll slack off the tension on the rod once it's all installed so the rod will be mostly to hold things in alignment if one or more of the joints does decide to fail over time.I guess after all this I better get a photo uploaded once it's done just to prove I actually accomplished something. Yeah, I'm married but if I don't get this thing done pretty soon that might change as well! (grin)
LOL. I understand the spousal issues with "learning curve projects". What about the sliding dovetail purlins? Unless you like the look of the hardware.
Mike
Hi Mike -I've enjoyed the discussion about ipe but quite frankly this will be the only and final project I embark on using this stuff! What a pain in the derriere!! Every precaution with regard to glue bonding; wiping with acetone, polyurethane glue even at the expense of the smallest lot of GG I could find, and still I get a joint failure! Beyond that I'm finding I need to wear latex gloves just to sand the stuff (hand sanding even lightly) I seem to have developed a sensitization to the stuff. As dense and hard as it appears, the dust is so laden with bad critters I'm goin' back to maple, ash and more user friendly wood types (grin).I did manage to get the towel shelf built and installed today so the better half is 'off my case' for a bit at any rate. And I'll admit that it's somewhat handsome. But three days to make and install a shelf .... well, let's just say it's a good thing that this is a retirement project!As for the dovetail purlins, it's a neat idea but yes, in this case the exposed hardware has become a design 'statement'. Another case of justification for having added an engine lathe to my shop stable. Being able to mfr. my own custom hardware is a plus since that's my main interest in life - making things.What with the holidays it will probably be a few days before I finish making the fittings for this bench but I think by now I owe you a photo of the finished product. Don't hold your breath but I promise, one is forthcoming.Thanks for all the comments and encouragement.
I like your candidness about getting to photos to us. Heh heh. I am certiantly am interested in your project. I've been using Ipe a lot lately since it is a relatively cheep tropical hardwood. But not inside and I would love to see it in a bath room.
I need a "friend" with a machine shop, and the knowlage to run it. It would be handy to call up "john" and ask if he could make some custom SS hardware! As I ofter tell my customers "I am done learning new things". I will continue to learn from yall about my chosen crafts, but no new stuff. No welding, machining, sculpting or rocket scientistry.
Mike
Mike -
Here are some shots of this infamous 'bench' beastie:
The SS 'plugs' are actually a bit over 1" long, blind drilled and tapped to receive the allthread. Not sure how at this point I'm gonna hide the big ol' nut & washer on the back side. Initially I thought it would be rather inconspicuous at the back but even after I get the excess allthread trimmed off I think it will be rather obvious. Had one thought perhaps I could just take the portable power hacksaw and cut through the nut and all to make it, the nut about half the regular thickness.
Anyway, best get the shop clothes on now that we're back from the family holidays and begin the cleanup of all that epoxy! At least it does hold the thing together.
AHH HAH. I didn't realize that you were only glueing small blocks between long slats. I thought you were edge glueing a solid panel. That makes a big difference. I'd say that you would have had long term problems with that design. Another way to get the same look with better joinery would be to use half lap joints so that the "spacer blocks" would actually be a continous piece of wood. However i like the look of the hardware. Not to mention you can point at it and say I machined that as well.
Mike
Thanks, Mike.Yeah,those little SS 'buttons' are the first actual finished machined parts I've made since getting the engine lathe. Got a lot to learn. Of course you can't see'em in the photo but there are a few tool marks on the faces. What is it they say? ...... character?? (hehehe)
Sounds like you have a shop that I (we) would love to see. Can you post pics?
Mike
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