Thread: Building Wegner's "The Chair" .

Thanks Ian.

Now I have been thinking a little down the line.

When it comes time to glue the parts together I thought that I would use West Systems epoxy (because it is gap filling) and mix in a little colour to disguise any gaps that may be present in the finger joins - they are likely only to be at the very tips of the fingers. I have saved up sawdust from sanding the legs, however I think that this will turn out darker than the surrounding wood. Should I test the finish on the wood and then try and mix with a complimentary colour, or not to bother with such a small area? Any thoughts and suggestions?

Regards from Perth

Derek

thoughts? Suggestions?

I'm not a great fan of epoxy for furniture.
PVA (or hide glue) is usually more than adequate

From what I can see your joints are tight.
I'd use PVA and treat any small gaps that might be present after final shaping with wax sticks during the finishing

Well Derek, I have to disagree with Ian on the choice of glue, but do agree that it would be far better to deal with gaps, if there are any, after glue-up. My few attempts at disguising holes or gaps with glue plus sawdust have been miserable failures - the sawdust/glue combination not only ended up a different colour from what I'd expected, it was a different texture, so the defects became really obvious.

My worry is that a chair back is a high-stress component that has to tolerate all sorts of abuse as well as normal forces. The shrinkage/expansion across the finger joints should be even, but may not be, & that might add stress on the glue lines. In any case I just don't trust PVA where there is any possibility of prolonged stress, and virtually all of the failures I've had with it have been on chairs (to be fair, my ignorance & poor design were factors, too). Hide glue would fit the bill better mechanically, and require less elaborate clamping,perhaps, but will also show against the pale timber if there are any gaps or less-than-water-tight joins. So I reckon clear epoxy is the better choice. True, it's not my first choice for any furniture, but you would hope this joint would never require dismantling, though I suppose one should never say never.....

Cheers,

I agree with both of you (!)

I prefer epoxy because I think it will cope better with the stresses here. The gap filling area is an non-issue. I expect that there will be a small gap at the ends of the fingers (as much as I try to get a tight fit there), and this would better be filled with coloured epoxy or a shellac stick, which will be easier to match at the end.

My priority at this stage is to shape the back and sides as much as possible - that is, remove as much waste as I can - leaving enough of the existing body to glue on anchoring points for clamps to pull the fingers together at glue-up time. Then it will be time to complete the shaping.

Regards from Perth

Derek

Derek

why do you doubt your ability to create a close fitting joint?

If it we were talking about dovetails, you would be confident that your joint had no gaps.

If I said make a dovetail box and once you have glued it together, shape the sides (cutting material away) to create a small bombe chest or tea caddy, you would be confident that the insides of your DTs were tight enough to be placed on show.


everything I've seen so far tells me that the joints you have created for this chair will be tight -- except perhaps at the very apex of each joint. An area where any small gaps can be hidden using shellac sticks at the finish stage

unlike the other Ian, I have faith in the ability of PVA to hold a well fitting joint together under normal stress -- and unless your chair is going to be used as part of a circus act by a 150kg acrobat, the back will only ever be exposed to normal stresses.
Remember the highest stressed joint in a chair is where the seat attaches to the rear legs. I suspect my 150kg acrobat will break the chair's legs well before they break the crest rail to arm joint.

I think its great you've found the time to finish the chair and entirely by hand. The result looks good to me. But I've only seen a couple of pictures ( I mean my judgment doesn't mean anything because I haven't been here for the whole process…..your results could be better than what I've seen….hopefully that deals with misunderstandings)

I was in a waiting room the other day, on these quite new factory made beech chairs with a similar joinery to whats used in this Wagner design,,,, and one of side rails was pulling free of the leg. I'm pretty sure they don't use hide in factory chairs, so uno, a modern PVA may not necessarily hold either.

I'd use Hide glue. And I'd pin (draw pin maybe) if you like those rail/leg joints.

The reason are...

- you'll have a mechanical joint (the pin) to support the glue. So the rails won't pull out.

- and you'll be respecting the process of repair. Because if its hide glue, all you need to pull that joint apart cleanly, is drill out the pin with a smaller diameter bit, use spreader clamps with even pressure and heat the joint. Can pour hot water over the joint and pin hole will help, because the water will flow into the joint easier, softening the hide,,,,and it will all come apart cleanly. If you use PVA, it can still be pulled apart with heat, but its so much harder. And the PVA will be dominating all the grain. You'll never get it out unlike hide. New hide glue will melt into old hide glue….. if you don't make that chair easy to repair, all that unique effort you've put into making that chair will be lost the day it breaks.

- the pin, imo, will actually add a nice little detail to draw the eye. That wagner chair needs something imo.

Thats just for the legs joints…. maybe epoxy would be better for those finger joints Ian was talking about…..ie. use two types of glue. Epoxy for the fingers, hide for leg/rails…..

just an opinion. I'm not an expert glue expert. I haven't studied glues all my life. I don't buy the stuff and roll around in it naked. 2cents worth.

cheers
Jake

I'm reasonably new here so have just spent some time reading through and catching up on this thread. This is a wonderful build Derek with a heck of a lot to learn from reading what you are doing and how you are doing it, thank you for sharing it.

Originally Posted by derekcohen

Thanks Ian.

Now I have been thinking a little down the line.

When it comes time to glue the parts together I thought that I would use West Systems epoxy (because it is gap filling) and mix in a little colour to disguise any gaps that may be present in the finger joins - they are likely only to be at the very tips of the fingers. I have saved up sawdust from sanding the legs, however I think that this will turn out darker than the surrounding wood. Should I test the finish on the wood and then try and mix with a complimentary colour, or not to bother with such a small area? Any thoughts and suggestions?

Regards from Perth

Derek

Derek, I've used epoxy quite a bit for gluing and filling with wooden boats and I find that I can achieve different shades by mixing very fine sawdust of the same timber with the glueing fillers/powder (but white, some brands like Bote-cote may be a sort of pink mud colour) that match the brand of epoxy that you are using.

It can take a bit of experimenting to get it right but the colour that you come up with when mixed is usually pretty close to how it comes out dry. Be sure to buy use the glueing fillers, not the fairing fillers. If you try a few mixes and let them dry before applying it to your chair you'll see how much colour change there is.

I use both West System and International Epiglass and each are equally good to use. The International is perhaps a little cheaper and easier to use being a 3:1 ratio mix where the West is 5:1. Both brands are usually available at any marine chandlers along with the glue fillers.

Where in Perth are you? I'm in Mandurah and have plenty of both West and International powders if you only want a small amount rather than having to buy a full bag for the relatively small glue up that you are doing.

Also, on gluing with epoxy, clear epoxy really isn't ideal for a strong glue joint. The high density gluing fillers/powders that the different brands provide for that purpose provide the gap filling properties and stop the epoxy from sagging and running out of the joint so that you get full coverage on all faces of the glue joint. Unless you build a dam to hold the clear epoxy any small gaps will drain of the epoxy creating a weaker joint.

(There are also low density fillers and they can be used for gluing but are not ideal. They are easier to sand than the high density fillers and are used to bulk out the epoxy for filling and fairing rough or uneven surfaces that will be later painted over. You can use wood powder to colour it but you obviously don't get any sense of grain so would paint it anyway.....unless perhaps you were just using it to fill gaps or small knots in a grain ?)

Originally Posted by derekcohen

I agree with both of you (!)

I prefer epoxy because I think it will cope better with the stresses here. The gap filling area is an non-issue. I expect that there will be a small gap at the ends of the fingers (as much as I try to get a tight fit there), and this would better be filled with coloured epoxy or a shellac stick, which will be easier to match at the end.

My priority at this stage is to shape the back and sides as much as possible - that is, remove as much waste as I can - leaving enough of the existing body to glue on anchoring points for clamps to pull the fingers together at glue-up time. Then it will be time to complete the shaping.

Regards from Perth

Derek

Derek

Do you really think that the stress in the joints, needs worrying over the type of glue ?

I have never liked. nor had real success with the sawdust and glue mix. They usually stand out from the surrounding wood and draw attention to themselves.


I would suggest the main issue for you may be the aesthetics of the joint, and will a few gaps be a greater concern with that wild grain and figure, would it not be a more satisfying solution to fill any gaps with a darker piece of veneer for example so they appear as a gum vein or other natural feature in the wood, rather than a fault in the joint.

If you are really fretting over having gaps appear after shaping, then the joint could be assembled dry by drilling a hole from the underside and fitting a pin ( perhaps metal ) that could be removed later. The joint could then be shaped down all bar the last few thou to reveal any discrepancies and dismantled to make corrections. A wood pin could then be glued in to complete the chair and also add greater strength to the joint.

Regards

Originally Posted by Basilg

Derek

I have never liked. nor had real success with the sawdust and glue mix. They usually stand out from the surrounding wood and draw attention to themselves.

same with me. The best patches, imo, is with timber of the same species used, with the grain running in a similar way to the surrounds of the patch.

Thanks for all the replies. They have given me a bit to think about.

I mentioned before that the gap filling is a non issue. Also that any filling - if needed - should be done at the end. Basil, I do not plan to mix sawdust with glue. It was only an early consideration.

It is difficult to tell how much gap there may be at the end of the fingers since it is the inside that counts and this becomes apparent later. The fingers are square, and the fit is pretty good, but I have been so obsessed with getting this joint shaped that I think I have become oversensitive to minor gaps.

Larks, I know what you mean about epoxy being runny. I used to repair surfboards and windsurfers with West Systems. It did slip my mind - thanks for the reminder. I am in Rossmoyne, which is also south of the River.

Jake, I do agree that hide glue is traditional for a good reason. I must admit that I have only used the premixed stuff (Titebond Liquid Hide Glue), and I am not sure whether this is good enough. I hesitate using something I am unfamiliar with. The factory used white glue, which does argue that I could use this as well (Titebond 3).

Regards from Perth

Derek

Originally Posted by derekcohen

Jake, I do agree that hide glue is traditional for a good reason. I must admit that I have only used the premixed stuff (Titebond Liquid Hide Glue), and I am not sure whether this is good enough. I hesitate using something I am unfamiliar with. The factory used white glue, which does argue that I could use this as well (Titebond 3).

Well….. when I was boy, I mean a lad… I mean



If you don't use hide -> your not interested in repair.

If the thing decides to move on you it doesn't matter what glue you use.

Do you have good air conditioning ? …. do you have a spot in the house out of direct sunlight ?

just an opinion. not an expert air-conditioning expert. 2 cents worth.

cheers
jake

Originally Posted by derekcohen

Thanks for all the replies. They have given me a bit to think about.

I mentioned before that the gap filling is a non issue. Also that any filling - if needed - should be done at the end. Basil, I do not plan to mix sawdust with glue. It was only an early consideration.

It is difficult to tell how much gap there may be at the end of the fingers since it is the inside that counts and this becomes apparent later. The fingers are square, and the fit is pretty good, but I have been so obsessed with getting this joint shaped that I think I have become oversensitive to minor gaps.

Larks, I know what you mean about epoxy being runny. I used to repair surfboards and windsurfers with West Systems. It did slip my mind - thanks for the reminder. I am in Rossmoyne, which is also south of the River.

Jake, I do agree that hide glue is traditional for a good reason. I must admit that I have only used the premixed stuff (Titebond Liquid Hide Glue), and I am not sure whether this is good enough. I hesitate using something I am unfamiliar with. The factory used white glue, which does argue that I could use this as well (Titebond 3).

Regards from Perth


Derek

Derek

Geoff Hannah is a long time user of Hide Glue and it was he that convinced me to use it, although admittedly, I did lots of experiments to test its use and strength just to be sure. I have used both Hot and liquid and am very very convinced about the strength of both, which is also reinforced by various reports, plus lots of furniture that is surviving after several hundred years.

Qualities of the glue I particularly like are the longer open time for the liquid, and its lubrication which permits difficult joints to be assembled without locking up. Additionally a joint can be sized before hand which retards starvation of the joint when the glue is applied on assembly, and retains full strength.


Regards

Originally Posted by derekcohen

I hesitate using something I am unfamiliar with. The factory used white glue, which does argue that I could use this as well (Titebond 3).

Derek

Is there an issue with black glue lines when using TB3. Perhaps TB2 might be better?

https://www.youtube.com/watch?v=8IdDrJOan2w

About the 2 minute mark.