Canvas stretcher

[artisan soldier]

Found this great idea posted by Wally Fay at The Picture Framers Grumble US. It basically allows framers to cut their own stretcher bars, without losing the ability of future stretching. Brilliant!



The full discussion can be seen here at the Picture Framers Grumble US.

David

[SquareFrames]

Hi,

Great diagram! But where is the abilty for natural expansion and contraction? Surely you cannot have the stretcher's mitre restricted like this, unless the turnbuckle has the abilty to expand and contract on its own. Even the use of 'Wedges' allows the bars and canvas to be at one with the natural or un-natural conditions of where the canvas is finally hung.

I never restrict the mitre (corners) of any stretcher bars.

For me, I do not know about everyone else, but there are far too many uneccessary gadgets / gismos coming into the framing world, this turnbuckle system would obviously increase the price of strecthing the canvas, so defeats the purpose, it obviously (as its metal) would add extra weight, again defeating the purpose.
One thing that also would worry me about this system, is the fact that to use it we make our own bars - most of us are not carpenters, most framers would not have routers with rounding over bits, so I take it that by making our own bars using this system, the canvas is against sharp corners??????? Canvasses need to flow over the bars, not be at right angles where incorrect stretching or tension will cause the canvas to rip or tearm but as I stated before my main concern is the inability ot expand and contract naturally. Please correct me if I am wrong!

For me, ther is nothing wrong with good old fashioned canvas stretching and wedges, tried and tested over many, many years, and in my workshop will always be used.
Steven

[artisan soldier]

Hi Steven,

Thanks for your reply.

In regards to the natural expansion of the canvas, the turnbuckle is just adjusted as required.

In terms of weight, the one turnbuckle I weighed weighs in at around 35g, so 4 @ 35g = 140 grams. I can't see this dramatically affecting anything.

The stretcher bars are just made from blank mouldings with a curved inner edge.

I would agree with you though, that there are way too many useless gadgets around which you don't ever end up using. Efficiency relies on developing a standard and maintaining it.

The main advantage of this system is the ability to be self sufficient. Even if this system isn't used exclusively, I think it still has it's merits.

David

[SquareFrames]

Hi David,

You quote

'In regards to the natural expansion of the canvas, the turnbuckle is just adjusted as required'

, that is the bit that is worrying me!

How do you know when 'Natural' expansion and contraction is taking place? I understand that the turnbuckle is adjusted accordingly when the canvas may look saggy, etc., but, and there is always a but, 'Natural' expansion and contraction has to be allowed to happen, and when it does, it doesnt mean that the client rushes off to their framer to get the wedges adjusted. To me, this turnbuckle system does not allow for the natural daily movement, it is restricting all movement of the bars and therefore eventually the canvas would tear ot rip.

Steven

[artisan soldier]

Steven

I'm just wondering what amount of `natural' expansion and contraction of canvas you have experienced?.

Certainly the further out the frame is adjusted the more likely the canvas will tear, but isn't this true of the traditional mortise and tenon system?

David

[John]

Hi David, welcome to the forum.

Seems like a perfectly cromulent idea to me, thanks for the tip.

Must get a few turnbuckles to have for those odd sized canvases that we seem to have had a run of lately.