Working on the demuline table, trying to bend apron. Tried one with PL400 worked well enough to find out my mold was out of square. but no spring back none.
Only used PL as I did not want to drive to town for glue.
so I trued up the mold, dry clamped laminations looks good and tight.
Does titebond III have a lot of creep to it?
If yes, could that be minimised by clinch nailing brass tacks, or bamboo scewers across grain, plugs for the lack of a better term. Veneer over top.
Thoughts??
I have tried to get hide glue, resinicol, Some other glue for bending no luck. would prefer not to use epoxy. Any body try PL Premium?
Living along a lake is nice but the shopping ain’t great !!
Replies
The Only glue I would trust with a bent Lam would be Unibond 800.I order on the net. Later Rickkk
I'm with Rickkk.
Beat it to fit / Paint it to match
The issue with PVA like Titebond in bent lamination is creep. It is a long-term phenomenon -- kinda like springback, but developing over months, not seconds. Non-creeping wood glues include epoxies and urea-formaldehyde (like Unibond 800). I think urethanes are non-creeping, but the one I've tried (Gorilla) for bent lamination pushed all the laminates apart as it cured, so the glue line was too visible.
I checked out the Unibond 800. It looks pretty good and not a bad price. I wonder if there is a Canadian dealer?
Looks like I'll use epoxy have to keep the project going
Thanks all
shoe
Veneer Systems has a Canadian Distribution in Ontario. I order from them. I recently was told about a supplier in Vancouver for a similar Urea Formaldehyde. I can track down the info if you like.
Brad
I would appreciate that.
ThanksI was rooting around and found some West system epoxy. As said not my first choice But!I did the glue up with 6 pieces of mahogany door skin, that was taken off 1978 doors.
Came out to 3/4. I drilled a few more holes in the mold for clamps. and all came out well.Cleaned it up this AM and started to veneer the lower edge. Cut and rough sanded the legs, top glued up and awaiting.Thanks all.Shoe in production mode
Edited 8/31/2009 7:18 pm ET by Shoemaker1
Casco-Resin made by Borden and distributed in Vancouver by Coast Fiber Tek (Burnaby).
The only disadvantage to epoxy is cleaning the squeeze out. It is awfully hard on sharp tools. Still a great choice. Both Urea and Epoxy require around the same clamp time.
Good luck
Edited 8/31/2009 7:24 pm ET by brad805
Shoe,For future projects, down here, Ace Hardware carries Weldwood. Do you have Ace up there?I'm with Rickkk and Hammer on the Unibond. If there are no cross boarder problems, Highland Woodworking /Atlanta carries it.http://www.highlandwoodworking.com/index.asp?PageAction=VIEWPROD&ProdID=7129Boiler
I'll keep that in mind. We don't have ACE hardware up here. Bringing stuff across the border can be costly.
The last thing I bought was a diamond grinder. cost in USD was 165.00 shipping in. buy the time I got it it was about 260 CDN with brokerage taxes and a few other charged just'cause.I finely got some Tite bond liguid hide glue today It only took 3.5 weeks but I got it this AM.
Thanks Shoe.
Hi Jamie,
I understand the creep issue in circumstances where the lamination is not restrained-- say the top rail of a chair back, or one of those free-form bent plywood chairs, or a curved cabinet door.
But, is creep really a factor in something like the poster's situation- the apron of a demilune table, where the ends of the lamination would be captured by the table's rear legs, and kept from moving apart by the rear apron being fixed to the rear legs?
How about a circular apron, with staggered lamination joins where the thing is holding itself in tension equally all round? Barring a delamination, where would the creep go to?
Having once, years ago, experienced catastrophic failure with weldwood glue (pieces falling apart right out of the clamps--does that stuff go bad as a powder in the can??) I've felt more confident using pva glue in both the above scenarios.
Ray
I assume that "Weldwood" is a powdered one-part urea formaldehyde glue, in which case, yes it does have a shelf life and so it could go "bad in the can" if stored for too long (e.g. over 18 months) or in damp or too warm conditions. I'm with the others who say that UF or epoxy is infinitely superior to PU or PVA glues both of which have their own problems (as noted above). As to separation not being I a problem I'd be in favour of avoiding the separation right off by using the correct glue rather than risk any potentially avoidable longer term problems.
Weldwood, I've tried to buy it along with hide glue. but no luck. living in the sticks has draw backs. I don't like buying things online as I had a credit card take on a life of it's own.Getting back to one point, if you put a few cross lamination tacks or bamboo scewers along the lamination would that have any effect on reducing creep?In the shoe business a few clinched brass tacks help resist delamination of leather soles. Most cement used for footwear is contact cement.Many years ago (pre creep knowledge ) I made a chest for my daughter and used PVA for the curved laminated ribs and it shows no sign of creep, but it has two screws every 4 inches.So as I scratch my head the question begs, can some mechanical fastners resist creep?Inquiring minds have to know!!
I have done several dozen bent laminations,including several types of glue, and my experience supports most, but not all, of the posted comments.
First, PVA glues do creep but the creep is not a problem in every application. It would probably not be a problem in a demilune table for the reasons posted.Second, fasteners would probably not solve a creep problem. The shear stresses that cause the glue to creep would also cause the fastener to damage the surrounding wood and allow the laminates to slip.Urea formaldehyde adhesives, either in powdered form or liquid, cure to a hard line, effectively preventing creep. The only drawback in my mind is that they are very temperature sensitive. It takes about 2 hours to cure at 95 degrees F, and about 12 hours to cure at 70 degrees F. That is a problem in a cool basement shop like mine. You need to have a sample of open glue next to your glue up so that you can test it periodically to see if the glue has set.I have settled on polyurethane glue for most of my bent laminations, because it cures to a hard line, is not temperature sensitive, and has enough open time for the glue up process. I have not experienced any problems with the joint opening up due to foaming. I do take pains to minimize the amount of glue. I first liberally coat one side with glue and then remove ~75% of it with a putty knife. This leaves enough glue for a good joint, but reduces the foaming significantly. I just let the foam cure and remove it after it becomes hard.Good clamping is a big issue. It takes a lot of clamps and careful application to avoid gaps. Some dry clamping is a good idea before applying glue.Based upon your comments, I would not worry about creep, but instead focus on your form and clamping process to get good results.Good luck, Tom.
Personally I wouldn't depend on any sort of mechanical fastener to resist creep. I don't think that they would stop delamination and I'd be concerned about them potentially telegraphing through the surface veneer in the long run. I've also seen a few cases where mechaniocal fasteners have sheared under delamination stress. It really is simpler to just use the right glue in the first place.I'd also second the comments by Tom77 re quantity of cramps. You can never really have enoughg clamps for a curved glue up
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