Repair split glue joint

[Freddyjersey2016]

I have been asked to fix a damaged Ercol loveseat - the planks (elm?) forming the seat seem to have split along the glue line. The splits are very narrow, so getting glue into them looks tricky.
It has been left for a long time in a conservatory - so I guess hot summers / damp winters have contributed to the split.
Photo attached
I am reasonably experienced DIY woodworker. How should I tackle this? (or do I pass, give it to someone more experienced?)
Thank you

 

[Mike.R]

It's difficult to tell from one photo but would it be practical to split the seat into two pieces, clean the join and glue and clamp back together ?

 

[baldkev]

Mike.R is probably right.
If you want or need to eave it in one piece, you could put glue over the crack and using a hoover underneath, try to suck it in. If that doesnt really work, you could blow it in.
Have you tried clamping it up yet?

 

[Cabinetman]

As above, but are you sure that it has actually cracked? You could tentatively try to open it further but be prepared to stop before doing any damage, the bits of seat are at least 4’ long and it only looks like there is a problem with the last few inches, which means you have a pig of a job, perhaps run away as you said! Ian
Ps extremely difficult to get cramps on that curved end as well.

 

[KevinLycett]

Clean and fill with wax stick?

 

[spanner48]

This is likely to be tricky; but – assuming [and ONLY assuming] I could get a sash cramp across the gap – I would use the 'Hot Araldite' technique. Put a heat gun onto the seat until the wood is REALLY hot - ideally close to 100ºC. Then make up a small dab of Araldite and just spot it onto the edge of the crack, as you progressively cramp it together. The glue will turn water-like, and the capillary action will pull it down into the joint. Cramp up fully; leave for 4 hours before uncramping.

That should make a strong joint, but I would also pin it with an oak 3/8" dowel, at an angle to the perpendicular.


Note also the need to cramp the joint up tight. At 100ºC, Araldite is NOT gap-filling.

 

[eribaMotters]

I see two issues, firstly the old glue is going to stop the new glue actually adhering with the timber and secondly getting it to cramp up tight.
If you can get it to clamp up, I would g-glamp a batten to the chair and run a thin kerf cordless circular saw through the crack to expose fresh timber. Titebond 3 would then be my choice of adhesive.

Colin

 

[baldkev]

Like colin said, g clamp a batten to the underside to keep alignment, but i would try a ratchet strap with ratchet on the underneath if you try to clamp it up.

 

[Cabinetman]

Thought I had better show just how curved the ends are, very little chance to cramp the last 9?” without something that resembles the waste left over from when the seat was cut out.

 

[Adam W.]

Get someone else to do it.

 

[recipio]

Have you a spreading clamp that will open the joint by a mm or so ? If so a slip of veneer will spread glue on the faces of the joint. Heat some pva glue in the bottle to help the glue flow. Of course you will need to get at least one sash cramp across the joint and you may need to cramp on a shaped piece of softwood to the edge of the seat to take the cramp. I'd do it indoors as pva is likely to fail if the temp falls below 6 degrees C.

 

[Mike.R]

It is a tricky shape to clamp.

I think I would make a cramping jig using two boards cut to sit around the perimeter of the seat and apply pressure with sash cramps.

 

[HOJ]

Looking at the picture is that the leg tenon showing thru the seat, just inboard of the last back spindle?

So if you sit down with your love and lean back or whatever, surely that's forcing that glue joint, may need a mechanical fix/butterfly joint, or keep it as an ornament.

I worked at the Ercol factory in High Wycombe in the 1980's but cant remember now, the glues used.

 

[MikeK]

I watch a lot of the Thomas Johnson furniture restoration videos. I think Tom would use a small spatula or craft knife to force lots of hide glue into the crack and then clamp it tight overnight. The excess hide glue wipes off with a damp rag.

 

[Yojevol]

I did a similar restoration of a couple of Ercol single chairs just a few weeks ago. I was faced with a similar split along a glue line. In my case the split did not go through to the underside and the seat felt basically sound. My solution was to fill the split with a very liquid epoxy. I needed to dam the end with bluetack to stop the epoxy running out.
I think it would be a mistake to attempt to clamp it tight. Any gluing is going to be imperfect and clamping will just reintroduce stresses which will cause the glue to fail again in the future.
Brian

 

[RichardG]

I would agree with @Yojevol. From my experience you'd never get a strong enough joint to overcome the twist of the timber. You either split the joint all the way, re-machine the faces and re-glue which is a big job. I've done this on a Ercol table top but I wouldn't in this case.

I believe the best bet is to stabilise the split to stop it getting worse and then fill it with wax to hide. I'd consider a butterfly underneath to bridge the gap at a couple of places or if you want something simple but less elegant (looking at the state of the piece it doesn't look like the owners value it that much) drill dowels in from the back edge.

 

[Jacob]

It's a weak design to start with - all leverage from pressure on the back of the chair goes straight to the glue line. Might have survived if it hadn't been neglected and left in a stressful environment.
I'd put a few repair plates across the split and further along the glue line, all out of sight underneath. Then just clean up the top and wax polish, filling the crack in the process.
If it carries on failing then there is no alternative to taking it apart and re joining.

 

[JohnPW]

One way to clamp is to glue blocks of wood with hide glue on either side of the joint, then clamp the blocks.

The blocks can be mostly carved away leaving a thin layer which can be soaked off.

 

[HOJ]

all leverage from pressure on the back of the chair goes straight to the glue line

That was my point, in a round about way.

 

[powertools]

If it is not yours and is still going to be kept in a conservatory after the repair just let someone else do it.