Oil-less Pneumatic Cylinders

by David on April, 2017  in News, Newsletter

Our machines use pneumatic cylinders that do not require frequent oiling because they have a permanently lubricated seal. Years ago it was a common practice to add a drop of oil once a week into the airline as a preventative measure.  Adding oil may have prevented the seals from drying out but it also created unforeseen issues. The air-born dust that was pulled in by the air compressor combined with the oil to make a “pasty” mixture that could clog the exhaust ports.

We still recommend adding a drop of oil once a week to pneumatic staple guns, but this can be done directly at the gun and not through the main airline.

How To Choose The Right Canvas Stretching Machine.

A veteran Custom Picture Framer would readily admit how tedious and time consuming it is to stretch canvas, to say nothing of the beating their hands take on a daily basis. There are some die hard veterans that will boast that they can stretch a large canvas as fast as any machine, doubtful, but it does pose an interesting question- Are you ready for a Canvas Stretching Machine?

With the advent of large format scanners, printers, archival ink and an enormous interest in printing art on canvas (giclees) there is a high demand for canvas stretching. Custom Framers, Commercial Printers and artists now find the need to stretch what they produce. So what should you look for in a Canvas Stretcher?

There are less than a dozen canvas stretching machines currently available on the market, both pneumatic and manually operated, but only a few are equipped to produce "gallery wraps", a technique that allows the art to wrap around the stretcher bar and the staples are hidden from view. If you do not have a need for gallery wraps then you can narrow your search, there are only 5 known canvas stretching machines that can produce gallery wraps.

To make an informed choice ask the manufacturer these questions:

How easy is it to load the art and reposition it? Do large pieces of art require assistance? Is the stapling done from the front or the back? Do you have to remove the artwork to make the folds? Is the artwork facing upward to reduce scuffs and marring? Is the operator free to move about when applying staples? How quickly can an operator stretch a large canvas? Can a 30" X 30" canvas be stretched in a minute, including the alignment? How portable is the machine?

The answer to these questions should help you make an informed choice, only you can justify the need for a Canvas Stretching Machine. However, if you stretch 20-30 canvases a week then you might consider such a purchase.

David Weaver is a retired Coast Guard Engineer Officer, Custom Picture Framer and the co-designer of the Gallery Stretcher-60, a Canvas Stretching Machine.

Giclee Prints - Cracking, Scuffing & Flaking

Large format Giclee Printers are much more affordable than they were 5 years ago, in the hands of an experienced operator the output is extraordinary. There are several steps to this process, regardless of the equipment, the artwork must be scanned, color corrected, retouched and printed to canvas or paper. The output, when printed on canvas, can be sold “as is” or it can be stretched. If you leave the stretching to the customer you are sending money out the door.

Stretching Giclees For those of us that stretch canvas there are a number of problems associated with stretching giclee prints. The most notable and perhaps the most annoying problem is “cracking” along the edges of the stretcher bar. A giclee print is nothing more than a thin layer of ink on the surface of the canvas. The ink does not penetrate the surface of the canvas and is easily separated when external forces are applied. The type of canvas, the weave of the fabric and the elasticity of the material all contribute to this problem. Scuffing and flaking can also occur when the artwork is moved across an abrasive surface.

Solutions that work

All giclee prints on canvas should be sprayed with a protective lamination with some form of UV protection. This will not eliminate cracking or scuffing but it will reduce it. The primary purpose of the lamination is to encapsulate the artwork; if the lamination has elasticity when it dries it will be less likely to crack.

If you are using canvas pliers you must avoid over-stretching the canvas. The primary disadvantage with using pliers is that the stretching force is not evenly distributed across the length of the stretcher bar. A typical pair of canvas pliers is only about 3” wide.

Avoid laying the artwork face down, scuffing occurs when the artwork moves against an abrasive surface (cardboard can cause scuffing).

A nice slow uniform stretch across a soft round corner over the entire length of the canvas is the primary solution to cracking. A canvas stretching machine would be the preferred tool, however, if you are forced to use canvas pliers try to emulate the machine.

Stretch the canvas slowly. Imagine the ink moving on a separate layer above the canvas, if the canvas moves quickly over a hard edge the thin layer of ink will tend to follow along that same plane until the canvas changes direction. Some of the ink will follow the canvas while some of the ink will “lift away” but stay on the canvas.

The stretcher bar should have a prominent “radius”, the larger the radius the less likely it is to have any cracking. Imagine pulling a strip of paper, with one hand, over the square edge of a wood table while resisting that pull with the other hand, note the drag. Imagine pulling that same strip over a rounded edge, very little drag. The hard edge is more likely to cause the paper to fray or part.

Summary In conclusion, treat the surface of the canvas with a spray lamination with some form of UV protection. Apply even stretching pressure along the entire length of the stretcher bar and stretch slowly. Be sure to use a stretcher bar with a prominent radius and avoid placing the artwork facedown.

About the Authors:

David is a self-taught Artist, Custom Picture Framer and Inventor. Greg Moulin is an accomplished Graphic Artist and owns the Frame Warehouse in Reynoldsburg, OH.