table top glue

[dennford]

I have been conned into making a large dining table for a nieghbour who is fool enough to think that I can do the job.

The table is fairly straight forward 4ft x 8ft 42mm thick tas oak top. 90mm x90mm tas oak legs fastened inside a tas oak skirt, the top will be fastened with those steel top clips that go into a slot.

Now this is how much I know - what sort of glue to use for jointing the top, I can't decide between pva, timbecons pvr or titebond 2. I reckon that any of them would do but I thought I may sound you all first.

Denn

[Hobbyhorse]

Denn,
I would use an epoxy however not everyone would agree with that.

Rhys

[Justin]

I'm a big fan of Titebond 3, it doesn't seem to creep at all.


Justin.

[dennford]

Denn,
I would use an epoxy however not everyone would agree with that.

Rhys

When you say epoxy, do you mean a two pack - similar to araldite? that'sthe only epoxy that I know of.

Denn

[dennford]

I'm a big fan of Titebond 3, it doesn't seem to creep at all.


Justin.

Is there any other differences between titebond 2 and 3?

Denn

[orraloon]

Denn,
As you said any of them will do. I have used pva and titebond 2 in the risers of archery bows and they are under a lot more stress than a table top. The success of a joint is in how well it fits and that it is clean before glue up. I clean the surfaces with spirit or acetone just before I glue them.

Regards
John

[Justin]

Is there any other differences between titebond 2 and 3?

Denn

Hi Denn,

I don't know mate, I went from Triton woodworking glue to Titebond 3, so I've never used 2.


Cheers,


Justin.

[scooter]

I wouldn't use a standard PVA, not because of strength but because the joint can creep, ie the joined components can move fractionally out of alignment. This can happen some time after glue up, leaving you with misaligned joints that had been sanded flush. On a tabletop this shows up as a very slight "step" between boards.

I'd go with an aliphatic resin type PVA (aka crosslinked PVA or "yellow glue") , these are resistant to creep.

Could also consider using a polyurethane glue such as Vise or Selleys Durabond.

Yellow glue - easy cleanup, economical, good shelf life.


Cheers...................Sean

[dennford]

That has given me more info' than I had - but it also means more to think about. Anyhow I shall let you know which way I go and also any problems or advantages that I encounter whilst gluing up the top.

Thanks for your input
Denn

[Hobbyhorse]

Denn,
I have used a lot of epoxy in laminating work in boats and have just about finished a wooden clock movement in which I made my own plywood out of oak and glued the laminations with epoxy with which I have made the cogs. The glue I am using at the moment is a CRC product which is two pot with equal parts as a ratio. I bought it from the local builders supply here in NZ and it is referred to as builders epoxy. Epoxy does not creep, sands well and gives a good strong joint. It also is good at gap filling where necessary.

Rhys

[jefferson]

Denn,

I've glued up stacks of bench and table tops out of Vic Ash, mostly using PVA or the "improved" Triton stuff.

You will have no worries using either - they say you can "guarantee" a stronger joint line than the timber itself.

If you use biscuits or dominos, you won't have any problems with creep either, just make sure your boards are jointed true and are fresh so that the glue sinks in.

One thing I did note from your original message was about using metal clips to secure the top.

I wouldn't. Without checking the expansion tables, a top over 4ft wide probably will expand +- half an inch at least over a season. That puts a lot of stress on those fasteners, even with KD timber.

I suggest wooden buttons instead, suitably "greased" with wax. Some of the metal fasteners I've used have been tested to the max - or rather, the whiteboard they've been attached to has protested. Accept the timber movement and allow for it - at your peril if you don't!

Jeff

[dennford]

It seems that strength is not going to be much of a problem - most of these glues will give a joint stronger than the wood itself providing I have prepared the edges properly. The main thing seems to be ease of use.

Jeff your comments on expansion are of interest - do you know where I can find expansion table? or should I say one that I (average intelligence - I hope) could understand.

Denn

[jeffhigh]

I would go with titebond 1 (original)
PVA glue creep is not just a problem with joints becoming misaligned, over time the pva glue can expand and show the lines. I have a tabletop I did 28 years ago with this problem .
PVA is also move difficult when sanding, softening and smearing, amd loading up the paper.

[BlackAdder]

Denn,

I suggest wooden buttons instead, suitably "greased" with wax ..... Accept the timber movement and allow for it - at your peril if you don't!

Jeff

G'Day Jeff,

The movement is also of interest for me, but not the expansion tables, rather your suggested method of "buttons". Could you explain more please? How do you use these "buttons", what do they look like, how do you prepare both mating surfaces?


BlackAdder

[jefferson]

Gents,

I just ducked out to the shed and found some basic info for you.

The "Furniture Design Guide" - which looks at Vic Ash, messmate and redgum - states:

"... a 100mm wide backsawn board of River Redgum will expand by .31mm for each 1% increase in moisture content. If the moisture content were to rise from 10% to 12% then the board would expand by 0.62mm..."

Vic Ash, according to the guide, will shrink or expand at a slightly higher rate - 0.35% for backsawn boards, 0.22% for quartersawn.

So if your table is say 1200mm wide, it can expand significantly - .70mm for a 2% increase in MC ie. 8.4mm. Double that if there is a 4% change in MC.

All this assumes you don't seal the table top (sealing slows the gain or loss of moisture very well).

Wood buttons have been around a long time and there's probably a thread or two on the topic somewhere.

All you need to do is cut a groove on the inside face of the rails, say 3/4 inch from the top. The wooden L-shaped buttons slot into the grooves and are fixed to the underside of the table.

You leave a gap between the rail and the button to allow for expansion, with spacing around 6-8 inches apart, maybe more.

Hope this helps.

Jeff

[scooter]

Small point - the Triton glue, while pale yellow in colour, is not a aliphatic resin type PVA, and as such could have the same vulnerability to creep.

I wouldn't rely on biscuits to prevent this, either, they aren't a precise enough fit to stop the miniscule amount of creep that your fingers can detect. Dominos are better fitting, so maybe, but I'd just use a better glue & not have the worry.

[dennford]

Denn,


One thing I did note from your original message was about using metal clips to secure the top.

I wouldn't. Without checking the expansion tables, a top over 4ft wide probably will expand +- half an inch at least over a season. That puts a lot of stress on those fasteners, even with KD timber.


Jeff

These would work the same as the buttons

[fatty500]

not trying to hijack the thread,

I've got a similar query, I want to glue down 5mm AD jarrah onto an old pine table. What glue would be ok to use, I don't want to use epoxy (fumes). Would AV260 2pk PVAc glue be ok, will it be strong enough to hold down the jarrah as the seasons change the MC%, and the thick veneer tries to buckle and warp, and will it last 20+ years. Will formaldehyde glue be significantly stronger and better?

Fatty

[dennford]

have just about finished a wooden clock movement in which I made my own plywood out of oak and glued the laminations with epoxy with which I have made the cogs. .

Rhys


Rhys,
apart from the obvious question (you must be a taffy?) how about some pic's of your clock movements?

To make a such a piece from wood that not only works but keeps accurate time is simply amazing.

I did once see clocks made by a man from my own area, and I still fijnd it hard to believe that these things actually work.

Denn

[dennford]

not trying to hijack the thread,



Fatty


Fatty, you're not hijacking the thread - just joining in the discussion.

Denn

[Different]

I swear by this glue 202-GF from Garett Wade

http://www.garrettwade.com/jump.jsp?itemType=PRODUCT&itemID=103111

It used to be available from /www.antongerner.com.au/ but i dont know if it still is or not.

Rgds

Ross

[jefferson]

Fatty,

I'm no veneer expert, but I don't think that any timber 5mm thick falls into the veneer category.

If you glue down timber that thick, it's gotta move. The thin wafers they use for veneer has lost its strength and ability to move. Suggest you glue down a wide test sample, wait a week, then sit it in a steamy bathroom for a few days and see what happens. Then stick it near the heater, just to be sure.

Jeff

[dennford]

Fatty,

I'm no veneer expert, but I don't think that any timber 5mm thick falls into the veneer category.


Jeff


Surely that's point five?

Denn

[Honorary Bloke]

Okay, let's see now.

What glue? Any good carpenter's glue will do:

Titebond--an aliphatic resin emulsion (Scooter's suggestion, I think). 5 minutes open time.

Titebond II- A cross-linked PVA. So please note PVA and Titebond II are the same thing. 5 minutes open time. Water-resistant.

Titebond III--Proprietary co-polymer. 10 minutes open time, an advantage for complex glue-ups but probably not necessary for a tabletop. Waterproof.

Despite some comments, all are easy to sand and clean up with water if you're quick smart with a damp rag.

Epoxy--overkill for a tabletop IMHO.

Polyurethane--you'll be sorry. It expands like a sponge and you will see the lines.

All PVA and similar glues like to creep, but careful clamping will prevent. Or use biscuits or Dominoes. I guarantee you'll still have to sand the top flush regardless.

Solid 5mm glued to solid top. A non-starter. 5mm is too thick. You can get away with it if it's plywood to plywood, for example, due to low movement. But not solid to solid.

Table buttons-- here's a link to a good thread. Lignum knows his stuff.

http://www.woodworkforums.com/showthread.php?t=49571


A 4 X 8 foot table is a real challenge and the largest glue-up problem may be finding a flat surface to work on. No flat surface = no aligned tabletop.

[jaspr]

Okay, let's see now.

Polyurethane--you'll be sorry. It expands like a sponge and you will see the lines.



I've been getting good results using polurethane glues in ed grain chopping boards - where you really need tight joint lines.

It works really well - but only if you "clamp often and clamp hard":). ie, it needs a lot of clamping pressure. It then only foams outside the joint not within it. So easy to clean up.

[dennford]

Solid 5mm glued to solid top. A non-starter. 5mm is too thick. You can get away with it if it's plywood to plywood, for example, due to low movement. But not solid to solid.

Table buttons-- here's a link to a good thread. Lignum knows his stuff.

http://www.woodworkforums.com/showthread.php?t=49571


A 4 X 8 foot table is a real challenge and the largest glue-up problem may be finding a flat surface to work on. No flat surface = no aligned tabletop.

The top is only going to be jointed tas' oak - nothing on top.


The buttton link was very interesting and although one of the final parts of the job, it gives me something to ponder on.

My nieghbour (the culprit who got me into this) will help me with glue up which I will start tommorrow - so I shall be preparing a suitable area today.

I still haven't made my mind up on the glue although there are a couple of favourites and a couple I have discounted..

Thanks to everyone again for all the help/suggestions, I shall keep you posted.

Denn

[Honorary Bloke]

I've been getting good results using polurethane glues in ed grain chopping boards - where you really need tight joint lines.

It works really well - but only if you "clamp often and clamp hard":). ie, it needs a lot of clamping pressure. It then only foams outside the joint not within it. So easy to clean up.

Valid point. But you are glueing small surface areas. I worry that an 8 X 4 table top may be more than can easily be handled. If you can do it, go for it. :) God knows poly is strong enough. :wink:

[sawdustmike]

I read that you are/have glued up, anyway my 2c worth. 2 pack epoxy does not creep, pva etc does. It is not the miniscule amount of movement per se that is the problem it is its effect on the laquer or whatever you seal with. It does not matter how you glue up any pva etc will creep. Some timbers are worse than others. Soft woods aren't so bad as the glue is stronger usually than the strain the timber can impart. Also epoxy has gap filling capability and has a long layup time, which you can vary. Either way your table top will be good experience. Enjoy.

[dennford]

just one last thing, no one has mentioned titebonds liquid hide glue which according to the spec would seem to fit the bill - wha'd'ya reckon?

Denn

[Honorary Bloke]

Hide glue will work. But no better than PVA. The benefit of hide glue has been its repairability and it is still often used in chair making for this reason. But you only reap the benefit of repairability if you use real pearl glue, not the Titebond, which is not repairable.

Neil has a section on Pearl glue in his book.

[dennford]

Thanks Bob,
It seems that the liquid hide glue question was pointless anyhow because after some phoning around yesterday arvo no one sells it in my area.

So the final decision is to stick (ha ha ) with Timbecons pvr - I reckon it will be adequqte and after all it is one that I have used before.

The job starts in a couple of hours.

Denn

[dennford]

Well! I'm glad that part is done. As someone said a table that size would not be easy.

My niegbour and I spent a good couple of hours preparing, first of all leveling up some bearers to work on and then doing a dummy run so that all clamps cauls and packing pieces were ready and where we could get them easy. We glued up using Timbecons pvr which gtipped a little bit faster than I would have liked, following the general consensus of opinion we didn't use biscuits or anything although they may have helped a little with alignment. As for alignment everything looks okay with the exception of two places where the mating board is proud by maybe 1mm so although I will have some sanding it isn't going to be excessive.

Denn

[Honorary Bloke]

Looking good so far. :2tsup: I'll bet that bugger weighs a tonne.:U

[dennford]

I'll bet that bugger weighs a tonne.:U

Your right there; mind you I'm glad he didn't want it made out of jarrah - that stuff is heavy - big time.

Denn

[brian mcmillan]

daystar 2 pak is excelent how ever its expencive and takes about 24 to 48 hours to fully cure but ive never had a top come apart!
or i also would recommend purbond pollyeurothane (645) glue the one i use only takes about 2 hours to dry and its good too

[dennford]

Well I unclamped it yesterday and it seemed okay apart from a few small ridges at the joins. Apart from an electric plane I only own a stanley/bailey no 4 - that was up untill a couple of weeks ago when I picked up this old wooden jackplane as in this thread http://www.woodworkforums.ubeaut.com.au/showthread.php?t=56319 . Anyhow I haven't done anything with it yet so I thought "why not try it out?", Well! what a pleasant surprise, without any work on it at all it did a beautifull job, So now the question is, how much do I do to the thing - probably fill the crack with epoxy and a good clean.

Denn

[johnc]

not trying to hijack the thread,

I've got a similar query, I want to glue down 5mm AD jarrah onto an old pine table. What glue would be ok to use, I don't want to use epoxy (fumes). Would AV260 2pk PVAc glue be ok, will it be strong enough to hold down the jarrah as the seasons change the MC%, and the thick veneer tries to buckle and warp, and will it last 20+ years. Will formaldehyde glue be significantly stronger and better?

Fatty
I've used AV260 on amongst other things 12mm hardwod flooring over 19mm pine and that has been down 15 years with no problems, however this is not recommended and I probably got lucky. It does allow for a very small amount of movement and is a pretty solid crosslinking PVA you should ring up the new AV260 owners (Bostick) and enquire to see if your application will work.

John

[scooter]

See this (http://www.woodworkforums.ubeaut.com.au/showthread.php?p=597411#post597411)thread for continuation of project.


Cheers.................Sean