Question Stretcher Bar Stock VS. Keyable Stretcher Strips

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monkey

monkey

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How do you decide when to use Stretcher Bar Stock VS Keyable Stretcher Strips? Needless to say when it is a valuable, one of a kind, original paining I would spend the money and use Keyable stertcher strips.

But, what if it's an original painting and customer doesn't know the value of it? How would you determine which to use? I offer my customer both options and explain the difference and they always choose the Stretcher Bar Stock option because it cost less. And if I only offer Keyable Stretcher, I won't be profitable.

For me, the Stretcher Bar Stock is much more profitable and easier. It come in lenght and I can chop it to the exact size I need and it's cheaper. I've heard that their is a very good chance that the canvas will sagg over time with changes in temp and humidity.

With the Keyable stretcher Strips, it cost more and it only come in 1 inche incraments. 99% of the time I get canvas sizes that are something like 39 5/8 inches x 23 3/8 inches. Does this mean I have to order custom made keayable stretcher strips $$ ?
 
It means you are getting in Metric paintings from ??

Someone who has a real value piece will opt for the custom bars.
And don't sell them a narrow black cheapo frame for it either.

Keep offering - - keep the education short and cheap... because
all they want if for it to be done and hung.
 
Is their a reasonably easy way to make strainer stock into a custom sized expandable stretcher bar?

In the past I used to get the next size up or maybe 2 sizes and then chop off the keyed part on 2 corners. I would join these with my underpinner and then use keys on the other 2 corners. This was not a perfect system, but did offer some ability to tighten up a canvas.
 
There is a system over here that is a sort of comprise. The moulding has a groove machined in it (some have two so you can have it deep or shallow). When the frame is made, I wack a few staples across the corners (so they don't contact the canvas) to hold it together. Then you cut some plywood triangles and fit them in the inside corners. This makes a reasonably rigid frame. When the canvas is mounted you can knock the ply triangles in to apply tension. You can't knock them too far though.... Some little screws in the grooves stops them slipping back.
I've sometimes made my own by cutting a groove in some std strainer with a table saw. The trick is to get some ply just the right thickness to get a nice snug fit. The bigger you cut the triangles the stronger the frame.

No substitute for keyed bars, but not a bad method if you are pushed.

And yes, I do get quite few metric canvases. :icon9: Can you get off-the-shelf metric size bars in the UK? can you f-fishcakes. :fire:


This is the sort of stuff in case my description don't make sense....

stretcher.jpg
 
The Jack Richeson expanding corner system will expand v-nailed bars so they can be added in the future if the painting droops. I have used and made other similar expanding corners over the past 3 decades. If it needs to be tightened you charge them for adding the expansion system in the future rather than today.
 
Jeff Rodier said:
The Jack Richeson expanding corner system will expand v-nailed bars so they can be added in the future if the painting droops. I have used and made other similar expanding corners over the past 3 decades. If it needs to be tightened you charge them for adding the expansion system in the future rather than today.
Click to expand...


Interesting. How can you expand the corners if they are V-nailed together?
 
Tensionable stretchers can be built from strainer stock using turnbuckles and a doweled miter joint. I've made the joint using 1/4" aluminum rods for the dowels. The dowels run through the stock perpendicular to the miter face, one closer to the inside, and one the outside. The dowel is secured at one end by through drilling and pinning it in place.
The eyes on the ends of the turnbuckles are bent to 45 degrees, and they are attached across the inside corner of all the miter joints. After the stretcher is assembled, the turnbuckles are tightened so the joint is drawn together, but not overtightened as to pull the joint closer than 90 degrees. The canvas is stretched and the turnbuckles reversed to force the joint apart and tension the canvas.

Using prefabricated stretcher bars, you can cut bars down using a scarf joint in the middle of the rail, securing with splines or biscuit joinery, and reinforcing with mending plates if necessary.
 
That's how I have done it with aluminum dowels going back over 30 years. The only difference is using L shaped aluminum screwed to the bars and a screw and nut to fasten the eye of the turnbuckle.
 
what I ended up doing

So I bought the next size up stretcher bars and miter them to the size I needed and recut new tenions. It really wasn't that hard, just a little time consuming. When done, it worked out really well.

Good excuse for me to buy a new japanese flush trimming pull saw, maybe dovetail saw, and maybe a bench undermount vise.
 

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For years I just added thin strips of wood to the outside edges of the height and width to ready made stretcher bars. Thus using the original corner mortices.
 
JFeig said:
For years I just added thin strips of wood to the outside edges of the height and width to ready made stretcher bars. Thus using the original corner mortices.
Click to expand...

That's one way I never thought of. (slaps head. :icon11:)

I made an odd size frame once using two sets fixed back-to-back. I cut them in different places so the joins were staggered. It was a biggish canvas so the extra thickness was a plus. Wouldn't like to do it on a regular basis though. Keeping the corner joints going the right way is fairly mind-boggling.
 
monkey said:
How do you decide when to use Stretcher Bar Stock VS Keyable Stretcher Strips? Needless to say when it is a valuable, one of a kind, original paining I would spend the money and use Keyable stertcher strips.

But, what if it's an original painting and customer doesn't know the value of it? How would you determine which to use? I offer my customer both options and explain the difference and they always choose the Stretcher Bar Stock option because it cost less. And if I only offer Keyable Stretcher, I won't be profitable.

For me, the Stretcher Bar Stock is much more profitable and easier. It come in lenght and I can chop it to the exact size I need and it's cheaper. I've heard that their is a very good chance that the canvas will sagg over time with changes in temp and humidity.

With the Keyable stretcher Strips, it cost more and it only come in 1 inche incraments. 99% of the time I get canvas sizes that are something like 39 5/8 inches x 23 3/8 inches. Does this mean I have to order custom made keayable stretcher strips $$ ?
Click to expand...

I'm sorry I didn't catch this conversation earlier. As it is true that purchasing length can be less costly, there are many benefits of using the tongue and groove bars with wood keys (or our BEST Corner Keys). The "purest" would not think twice about the T & G and educating the customer on the benefits of a specific bar may help. But, some customers don't care.

JRC offers custom tongue and groove and pricing is very reasonable. "Custom" doesn't mean expensive...it just has to be hand-cut.
We have shown our BEST Corner Keys on underpinned canvassed pieces. Yes, it does break the corners apart and you may go as far as 1/8 inch to open it up. The key and the canvas maintains the structure of the frame.

The Best Corner Key is designed specifically for tension adjustment after stretching or in the future due to climate change. Minimal cost to put on frame and you become a hero. It might take all of 10 minutes.

Give me a call...I'd be happy to introduce you to BEST Stretcher Bars where you can enjoy the services of a reliable brand.
 
Just in case anybody is puzzling over the stretcher bars I was trying to describe....

This is a in-house version made by cutting a saw groove in 19mm deep strainer.
The triangle is 4mm plywood which fits snuggly in the groove.

stretcher001.jpg


The staples are just there to hold the thing square while you put it all together.
Two either side is plenty as you want them to give when the frame is tensioned.
A tap with a hammer will force the corner apart. With a bit of practice you can
move the corner in both directions.

stretcher002.jpg


A little screw in the groove will stop the triangle from slipping back once the tension is applied.

stretcher003.jpg


As I said, it's not as good as proper keyed joints but it works quite well.
I find it handy for touristy bed-sheet canvases that are always an awkward size.
You can make the triangles bigger according to the size of the canvas. You can even
make cross-bars from plywood and wedge them in the groove.
 
Peter, that is absolutely brilliant! If you cut the dado deep enough you can eliminate any twist as well.
 
Darn it, Peter, I've been trying to resist getting a table saw for all these years. You are making resistance more futile.
:popc: Rick
 
My saw is only a cheapo one, but it does the job. I made a sort of jig to guide the wood though and stop it wandering about. It also makes the operation safer, as you have to remove the parting knife and safety guard on mine to be able to cut part-way into the wood.
 
monkey said:
Interesting. How can you expand the corners if they are V-nailed together?
Click to expand...

You will actually be breaking apart the underpinned/glued corners and using the BEST Corner Key. Opening the corners approx. 1/8" max will adjust the tension of the canvas. The Keys continue to hold it together while not compromising the strength or potentially damaging the canvas.
 
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