Thread: New (?) Glue for laminating benchtops

Thanks Zenwood, I'd send you a greenie thing, but as a jube to the forum - I aint good enought to be trusted with that power yet
In reference to the breadboard thing, it will not be neat will it? I mean the laminated section will expand and be wider than the end piece is long; then shrink and be narrower... I am a bit of a neat freak, in some things anyway. I guess I need to be looking for a table of movement values for Aussie woods.
Aveagoodone
BTW before I try out the glue on the bench, I am thinking of making a laminated butchers block - anyone know if there are timbers that you just should not use??
What does AFAIK stand for - Alien Forensic An*l Investigation Korps??

Originally Posted by Clinton1

In reference to the breadboard thing, it will not be neat will it? I mean the laminated section will expand and be wider than the end piece is long; then shrink and be narrower... I am a bit of a neat freak, in some things anyway. I guess I need to be looking for a table of movement values for Aussie woods.

Clinton1, you're never going to find a wood, local or otherwise that doesn't move a bit with the comings and goings of humidity, and the wider the piece, the more it moves. If you 'breadboard' a top, then you have to accept that sometimes the end is going to be too wide or too narrow by a mm or two. So if that is offensive to you, you need a design that will hide it.

The old-style European bench design does just that. It has end-caps which have important structural roles. One end carries the nut for the tail vice, and the other helps to retain the fixed arm of the shoulder vice. The caps are usually dovetailed to the back piece, and because I don't build shoulder vices (never had the space around a bench to accomodate one), I dovetail the front apron intop the left side cap too. This may seem a bit counter-intuitive, and a recipe for self-destruction, but movement of the top is catered for by the tool-tray design. Some people don't like having a tool tray on the bench top, because they fill up with junk, but it solves the problem of wood movement, if you build it correctly.

Modern steel vices can usually be mounted without the need for end caps, so if you're using these, no need to bother. Even if you want a tool-tray, these can be screwed to the back edge quite successfully, without having to be built-in....

Avagooday

AFAIK: As Far As I Know. Ckeck out

http://www.acronymfinder.com/

Breadboard neatness: if the bench is a workbench, IanW has excellent advice. If it's a kitchen bench, you might be able to achieve neatness on the front edge by glueing the front tenon, and dowelling the middle and rear tenons, thus forcing the expansion, and resulting planar mismatch, to occur there invisibly. A friend of mine achieved kitchen bench neatness by adding a mitred frame to the font and sides. Not sure how he attached the perpendicular grains: I might ask him.

Thanks for the gray greenie! Let us know how it all works out.

BTW (By the way) you need a new avatar: that one is disturbing!

Originally Posted by zenwood

A friend of mine achieved kitchen bench neatness by adding a mitred frame to the font and sides. Not sure how he attached the perpendicular grains: I might ask him.

Zenwood - While a mitred frame might achieve neatness, you are going to need an expansion gap somewhere to allow for seasonal comings and goings of the contained wood, otherwise the mitres will almost certainly pop. The wider and thicker the top, the more power it will develop.

I not long ago repaired a tabletop that had been enclosed in a 45mm thick Kwila mitred frame. The mitres were not the most accurately cut ones I've ever encountred, but the maker had managed to force the tops together to the nearest 3mm or so, and made up the rest with several kilos of epoxy. He then drove a couple of 5/8th hardwood dowels through each corner, replete with more epoxy, in a vain attempt to constrain the 45mm thick hardwood it was surrounding. Of course, the wood won, popping two corners and breaking the dowels in the process.
I couldn't pursuade the owner that the design was fundamentally flawed, so repaired it to their demands, with an expansion gap in the panel, (and slightly bettter-fitting mitres!). They also wanted the panel changed to Silky Oak (G. robusta), which is much softer and more compressible, so maybe it will hold up a bit better this time, but I gave no guarantee!
Just a good reminder to me how much force expanding wood can develop.
Cheers,

Are there any good web based tutorials in exactly what kinds of design flaws can lead to problems and how to overcome them?

I'm a complete novice, and I'm concerned that some of my designs on a current project may create problems when the wood moves.

antisense. ^_^

Antisense - there must be, but if Google can't find you some, almost any basic w'working book starts off with a discussion of wood movement.
In essence, there is little mystery to it. Wood is a bunch of cells whose thick walls are made of hygroscopic material. As the cell walls take up and gives off water, according to prevailing humidity, they expand and contract. The cellular structure is such that nearly all the change occurs in the diameter of the constituent cells, and negligble change in length.
So when designing something made of wood, you just have to remember each piece of wood in it is going to get fatter and leaner as the seasons roll around, and find ways to allow for that without constraining the movement too much.
The emphasis is on 'too much', because some joints such as a rightangle mortice and tenon necessarily constrain wood movement. But if the width is short, it can't develop too much power, so the annual movement can be contained by the glue and the elasticity of the material constraining it.
But when you get very wide pieces like table tops the total movement is a lot, and the power they devlop is great. The thicker the top, the slower it moves (takes longer for water vapour to go in and out), but the more power it develops. So that's why wide tops are screwed to aprons with wood or metal buttons, or screwed through elongated slots. Wide panels are allowed to 'float' in a frame, etc.
I'd be willing to bet all of us have made design mistakes at some time or other - there are situations where you just have to bend the rules a bit. Sometimes you get away with it (for a while, at least) and sometimes not.
Softer, compressible woods are the most forgiving. I've repaired a few old cedar sideboards that were glued up with hide glue, with parts like the plinth glued cross-grain. For years the wood took it, but eventaully, due perhaps to some sudden change, the sides split, or cracked the glue, or both.
They used crappy construction methods a hundred plus years ago, too!
Cheers,

Scooter - That's the AQUADHERE DURABOND:

is a polyurethane woodworking adhesive that produces bonds stronger than most woods. It is waterproof and adheres wood to a variety of other surfaces (eg MDF, metal, glass, ceramic, concrete). It's also sandable, paintable and stainable for extra workability.

http://www.selleys.com.au/products/live/306/202.asp

I'm getting ready to do my own bench. I'm planning to use Gorilla Glue. AFAIK, Gorilla is comparable to Durabond. I was thinking about yellow glue, but I want to finish the bench sometime in this century ) I think yellow glue is too slow to set to where I can unclamp and do more boards (I could use about a bazillion more pipe clamps).

I can unclamp joints glued with the gorilla glue in a few hours and start the next set. Squeeze out with the poly glues is a PITA to clean up when dry, though, so take care with it. Wear gloves, too!

The best glue for bench top laminations is resourcinal glue. Long open time, about 2 hours, exceptional strength, does not creep. Weldwood is one brand that I have used. Boatbuilders use resourcinal glues. Clean up the squeeze out as soon as you are done glue up. Cover the floor or table with plastic as this glue is tough to clean up.
I once did a spiral stair stringer lamination with this glue, did not protect the subfloor. I spent 6 hours cleaning the globs off the plywood.
I have built many benches, almost all of them were glued up with pva. Works fine, but you do have to work a bit hurried. Since I switched to resourcinal glue I have time sip a cup of coffee while I work.

mike

Zenwood - So you are disturbed by my avatar, its from the Gorillaz band website. It represents me when I see a flash new tool and I don't see the 4 in front of the 40.00 ($40 ) on the price tag ($440 ) ... or when I see 'doug the slugs' avatar.
I'll try to get a calmer one for you.

Originally Posted by Clinton1

Zenwood - So you are disturbed by my avatar[...]

doug's is definitely one of the better animated avatars (generally I find the animated avatars distracting--in a bad way). If the av represents you, I'd hate to be that tool, or doug's av:eek)

What was the tool, BTW?

What does AFAIK stand for - Alien Forensic An*l Investigation Korps??

On of the better explanations . . .

Originally Posted by zenwood

What was the tool, BTW?

Now 'es gettin' personal!
Had to get in before Ozwinner!

The tool was my reflection AND a shiny, bright steel, english made, (maker/manufactures name eludes me) rebate/fillister plane with ..... looked it up on the web: Clifton 3-option rebate plane no. 3110 (Found the link on google - first to list was - http://www.fine-tools.com/esims.htm ) why is my keyboard wet??? oh, thats my drool