Upholstery WIP - chair from scratch

[q9]

Yes I'm probably overcomplicating what doesn't need to be any more complicated.

Nice build sofa...

[Christos]

.....Nice build sofa...

Thought he was building a chair?

[Arron]

Nice build sofa...

Spare me. Even a chair is doing my head in.

Next will be a chaise lounge though.

Cheers

[Arron]

Nothing confuses me more then foam rubber. I guess the main things I'm uncertain about are how thick and how dense the foam needs to be. I also dont know to what extent I can rely on the fabric layers to round over the sharp edges of a foam cushion. And I dont know to what extent I can rely on the batting (wadding) layer to smooth out any sharp edges.

I guess the only way to learn is to go ahead and make mistakes. So today I did the foam layer.

The foam layer I need is basically a complex 3d curve. If I was making this commercially then I would probably have a moulded foam insert to drop in. I dont so I have to make it up from mulitple layers. First I glued a 10 mm thick soft foam layer over the whole surface using contact glue. Then I glued 2 layers of 25mm firm foam over the top, bought from Clark Rubber for $17. I bevelled their edges at 45 degrees in case the next three layers of fabric and batting are not sufficient to smooth them down. Here's the look:

foam.JPG

I cut the bevels on a bandsaw. I recently had a bad near-miss on the bandsaw cutting poorly-supported timber so I'm more then usually jumpy. Hence I made a fixture which kept my hands well away from the blade. Here it is:

foamCutter.JPG

The fixture is clamped to the bandsaw table, and the foam is fixed to a piece of thin plywood by a tiny piece of double sided tape. The plywood is slid along the fixture with just the foam passing through the blade. Curves take several passes. Its safe.

cheers
Arron

[q9]

Corners need sanding off round, and it works better to put the small piece of foam behind the big one. The other way around you will see and it will annoy you no end.

[Arron]

Ok, thanks. I will make the changes.

Cheers
Arron

[q9]

When I used to do foam backed office chairs we had a custom made sanding spindle, basically just a piece of wood turned to the desired shape and some fairly coarse grit paper glued on. It will never wear out on foam

Any, and I mean any, straight line will show through the fabric. The idea of using something like acrylic wool sheet I've the top has merit...

[Arron]

I was hoping to be able to just put it on my 'big boy' sander tomorrow. If that fails then perhaps I'll glue some 60 grit to a broomstick and put it in the lathe.

I'm not sure what is meant by 'acrylic wool sheet'. I have polyester batting which will go over the top. This stuff "Dacron" Bonded Polyester Fibre (PER METRE) | Home Upholsterer . Same effect ???

[Arron]

I want to say thanks for your help too. This is just the kind of input and learning along the way I was hoping for.

Cheers

[q9]

Actually this made me remember...one of the lines we used to make was a high back chair. You could get the premium version which had extra lumbar support. In truth it was just a few cents worth of high density foam, about 4x1 inch glued behind the normal foam. It took maybe an extra few seconds to glue it up.

Wholesale price at the time would have been well more than all that!

[q9]

Oh yeah, that fibre sheet should do nicely.

[ian]

Hi Arron

another tool for cutting foam is a jig saw with a foam cutting blade.
Festool and Bosch both make foam cutting blades. The Festool ones are 150mm long, and the Bosch ones about 100mm (I think). Cost is around $7 per blade and they are sold in packs of 3.

[Arron]

This morning I separated the foams and reglued them as advised. I shaped them on the 'big boy' sander, which is very aggressive but usable. I put the small piece behind the large piece too. There is a bit of residual glue but its minimal and I'm pretty sure it wont affect the finished job.

foam2.JPG

One thing I'm wondering about is the gap between the top of the foam and the top rail. There was meant to be a gap here but not as large or as deep as it is. I'm concerned it will feel hollow once the fabric is on. I have lots of loose dacron fibre that I could use here to minimize it. Would it be a wise precaution, or should I wait till the layer of calico and wadding are on and see what remains ?

cheers
Arron

[q9]

I was going to answer this earlier...so my short answer is it would be better no gap. Well sanded, the top most section will compress down nicely. You could try adding extra to the top like you were saying, but I'd guess it won't be satisfactory. I should have picked it before. Gomen!

Joining a new piece on top or underneath might be ok, but it will need to be a near perfect join.

[NCArcher]

Could you add in a strip a couple of inches down from the top. The top is already shaped and a join on the flat section would be easier to get flush/even.
An electric bread/carving knife is excellent for cutting foam.