Glue recommendation for staircase build

[glynster]

I've built my first staircase in solid oak using traditional methods only - except the stringers are made with a jig and will be wedged with softwood (big props to Mark Milner's "Simply Stairs" book). Its only a half flight going between split levels but it includes a landing which I made.

I am just about finished and ready for assembly and was wondering what the stair builders out there could recommend in terms of the best glue for the job - super strong, flexible and a good gap filler. The stringer tenons are draw-bore but a couple of them are a bit sloppy (i.e. not loose or very gappy but not a friction fit and being twin, haunched tenons I am sure there's some voids in there to fill out).

I have a ton of yellow Titebond but I'm concerned that that might be too brittle for anything but the treads and risers and its not a gap filler. I am tempted to use epoxy for the stringer mortices - will it cope with a bit of flex? I have been using the foaming poly glues a lot recently and really like the speed and slight gap filling but since I need to sand down before assembly I would be worried if it foamed too much and gave me a big, awkward re-sanding job - plus I am not convinced they gap fill with any strength. I've seen a few Yankee sites recommend "Construction adhesive" but I have no idea what that is or if its the same thing over here - if its anything like Gripfill or no more nails I cant imagine thats a serious recommendation - our American friends do do things a bit hokey sometimes - their staircases are all nailed and make use of metal L brackets and the likes.

I'm happy with the idea of using more than one glue on the job - I'm looking for some hard earned experienced knowledge.

Thanks

 

[Brandlin]

yes construction adhesive is no more nails

 

[PAC1]

I have only ever used tite bond type glue. Also all the staircases where I have seen the construction in the uk used the same.

 

[MikeG.]

I certainly wouldn't use PU. I think their structure is too brittle to cope with long-term movement. I would never even contemplate "No More Nails" or anything like that. I'd also suggest that you find something with a decent open time, because a stair glue-up isn't a 5 minute job.

 

[ED65]

I have been using the foaming poly glues a lot recently and really like the speed and slight gap filling... not convinced they gap fill with any strength.

Yup, foaming polyurethanes have basically zero gap-filling ability. Yes the foam fills gaps but that foam has zero structural strength.

Using more than one glue is exactly what I was about to suggest – one for the gappy joints and something else (i.e. white or yellow PVA) for the rest. If you did want to use just one then epoxy for the whole job, although it can work out very expensive.

Epoxies are now widely used in boatbuilding, meaning they can handle more flexing than your joints should exhibit so there should be no worries on that front.

 

[glynster]

Thanks for all of the advice, I think I will use standard yellow titebond for the treads and risers, wedges etc and Epoxy for the stringer and handrail mortices - I had forgotten that Epoxy was the glue of choice for boat building and so it must have some flex(in my mind I saw epoxy as steel-like in strength but brittle but I guess not). I might try the West system epoxy - is it right you use a filler when using it for gap filling or is that just for big voids? For example, some of the tenons are tapered as opposed to square and I am sure the bottom of the mortises are not an exact match as a result as I drilled and chopped them out by hand.

 

[user22161]

In the boaty world, colloidal silica is often used for thickening or sometimes micro fibres. West also do a thickened epoxy which is said to be good with wood but I've no personal experience - https://www.ecfibreglasssupplies.co.uk/ ... y-adhesive

 

[custard]

Epoxy isn't flexible, it's brittle when cured. There are specialist epoxies that are more flexible, in the same way there are specialist epoxies that are more heat resistant, but it's worth noting that standard epoxy and standard UF glues are regarded by many experienced furniture makers as too inflexible for chair making.

Maybe that doesn't matter? There are a couple of experienced joiners on the forum and their thoughts are the only ones worth listening to. I've been a furniture maker for forty years, but I haven't a clue about joinery adhesives, especially in a technical application like stair making.

 

[user22161]

When used properly, not as brittle and likely to fail as you may think. Standard 105 resin is used for wooden boat building and the structures have to remain flexible as when used with glass or carbon fibre. Maybe G/Flex resin would be more suitable for stairs. but rather expensive.

 

[ColeyS1]

The glue I use depends on what timber the stairs are made from. Mdf treads and risers are normally glued together with white pva. The glue blocks would also be glued with white pva. If the strings are hardwood (most hardwood stairs I make are oak) I'd use titebond 3 for gluing in the softwood wedges.

If it were an entire oak staircase I'd use titebond 3 for all of it.

It's very rare I ever glue strings to newels or handrails to newels. I use half inch tapered drawbores for joining strings, and 3/8 drawbores for the handrails.
The few times I have used glue for joining newel posts to strings is when the newels have needed larger than normal notches to hook over the apron.

Sent from my SM-G900F using Tapatalk

 

[MikeG.]

I've never (yet) made stairs, but I've bought and fitted quite a few over the years, and observed plenty of others after fitting. I've noticed this about the glue: first of all, they slather it about everywhere. There's loads of it, dribbling out of every join, and particularly around the wedges. Secondly, it was always normal white PVA whenever the stairs were MDF, ply or softwood in whatever combination, but it was Titebond 3, from the colour, with the oak stairs.

 

[HOJ]

As outlined by ColeyS1 for all the stairs I make, PVA or Titebond 3 and draw bore.