In honor of this month's equipment showcase, I want to discuss mounting presses, their size limitations, and some biting solutions. Wouldn't it be wonderful if we lived in a perfect world of framing where every project you needed to mount always fit comfortably within the confines of your mounting press?
Often vacuum presses are large enough to accommodate most of what may be encountered, but then Marilyn Monroe or Michael Jordan walks through your door and no matter what you do they simply won't fit into the press without performing a magicians self-healing midriff dissection.
Cutting the project into two pieces is only one solution to the oversized mounting problem, and it may not turn out to be the best choice. When limited by the outer dimensions of a vacuum system, alternative solutions need to be sought out. Locating a larger vacuum press and subcontracting the project is one choice; mounting by hand through the flexibility of wet, spray or pressure sensitive is a second solution; or use a mechanical (aka softbed) or hardbed press which allows for mounting the project in bites.
Biting by Definition
According to Webster's Dictionary of the English Language the slang version of bite means "an exacted portion", which is precisely what occurs when mounting a large job in steps or stages with a mechanical press. Since the action of mounting involves numerous times the artwork is held in the press, it translates into taking smaller bites (exacted portions, determined by the platen size). These smaller bites added together can ultimately accommodate oversized mountings, such as Marilyn Monroe.
Determining Maximum Dimensions
Since biting is the systematic division of a large item by pressing smaller sections until totally mounted, the size of the press platen determines the overall artwork allowed to be mounted. The project may only be a little less than twice the platen width since it can only be mounted once from either side. There should be about a 2" overlap at the center when mounting from both sides.
If total platen width is used to determine maximum project width there is a risk of leaving a tunnel of unmounted artwork through the center of the project. A press with a 26"x 34" platen will accommodate a maximum suggested two-bite project would of 2 x 24" or 48", or 2" less than actual platen dimensions. A smaller 18-½" x 23" platen will mount 2 x 16" or 32" wide. The project could be of any length though, with the only length limitation being press location in relation to shop walls and other equipment.
The outer dimensions of the mounting need to include the overall size of the selected substrate, so if mounting a 20"x 30" poster centered onto a 26"x36" board, it will not fit into the 32" width maximum of a small mechanical press. Don't get caught by not thinking things through.
Procedures and Adjustments
As with any mounting, but especially when mounting in multiple bites, the equipment must be set perfectly. When a softer substrate of foam board is selected, there are two things that will always prevent any dents when biting.
First, the handle of the press MUST be at 45 degrees to the table - in the closed but not locked position - with all items to be mounted set in the press between the platen and the sponge pad. If the press is set too loose - handle at less than 45 degrees - bubbles could occur, the result of inadequate pressure during mounting. Too tight - handle greater than 45 degrees- will almost guarantee indentations in a foam substrate. The handle will require readjustment or shims if a 4 ply or ⅛" foam is used after setting everything for a ³⁄₁₆" foam base, see "TTPM: Pressure", March 1995.
Second, a release board about two inches larger than the platen MUST be used on top of the mounting sandwich.
This will help dissipate the pressure at the bite point at the edge of the press. Compare stepping into a mud puddle with one foot and sinking up to your ankle. Now lay a sheet of 4'x8' plywood down, step on it and there will be no mud in your shoe. This is the concept of a release board at platen edge.
The best adhesive for a project of this type is a permanent, breathable, tissue-core sheet (Seal/ColorMount, TechMount 2, Drytac/Trimount...). They bond as they reach temperature within the press and will not release with subsequent bitings.
Tack and Bite
Once everything is adjusted, sized and pre-dried, the poster, photo or artwork must be tacked so as not to shift when placed into the press. Although Z-method tacking is highly suggested in order to keep the iron from coming into contact with the artwork face, in this case it could promote buckling of the art and tissue. Multiple bite mounting is specifically a time in which surface tacking is the mode of operation. Surface tacking merely indicates tacking through all layers from the surface, in one location along the top or side of the project where the mounting will be fitted into the press first.
When tacking a one step mounting, the placement of the tack is never as important as when multiple bites will be made. The tack must be the point of the initial bite, otherwise a pucker or wrinkle could occur. It is also important to place the project into the press allowing maximum overlap to ensure full bonding. If a project requires two bites, tack the end rather than the side, and place the tacked end into the press first. Always turn the mount board around for the second bite to reinforce good habits. Even if the substrate fits between the back press hinges the practice of turning the project around to mount the second half will prevent possible damage to the soft edges of a foam board.
If mounting in four bites, the tack point will be offset to one corner rather than centered on the side. This tack point will always enter the press first. With four bite mounting it won't matter whether you rotate adjacent to or across from the initial mount (clockwise vs. counterclockwise).
Longer oversized projects requiring 6, 8 or more bites should be tacked at the center of one of the long sides which will be placed into the press first. The second bite will be directly across from this initial tacked and mounted bite. From there work towards the outside ends of the project either right or left, and depending upon the overall length of the piece it is best to bite directly across as you progress to the end.
By mounting across from each successive bite the longer artwork is better kept from shifting or being mounted out of proper alignment. As with stretching a canvas work from the center to the outer ends. This reinforces placement and helps prevent wrinkles or air bubbles. Overlap all bites as much as possible to prevent unmounted tunnels between the bites. This also supports the substrate better to assist in aiding against dents by never pressing the same bite point.
Alternatives and Dollars
If biting remains an impossible solution to your Marilyn Monroe dilemma, remember alternative solutions include subcontracting, wet, spray and pressure sensitive mounting. Any time alternative procedures are necessary to accomplish a project which increases normal mounting time, additional charges should be included in the price. Always take into account the additional labor time incurred in dropping off and picking up subcontracted work and include these expenses in your charges to the customer. If selecting one of the hand applied solutions, pay attention to TTPM rules involving open/dwell time, weighting, as well as ventilation and clean up.
Never undertake an oversized project without realizing the additional time, energy, and effort that will go into it, and always charge for it. Since oversized artwork also means oversized mats, glass, fillets and frame which indicates an overall higher priced, higher profit project in the first place, an extra hour shop time in relation to the mounting is easily absorbed into a $500-$700 job , and worth every penny I might add.
Whether you decide to bite or not to bite, will best be determined by your facilities, the number of oversized projects you routinely tackle in a month and whether you own a mechanical press or not. The best part of having a press with the capability of biting is that not only can you two bite, you can also four bite, six bite and more!
Copyright © 1996 Chris A Paschke
For more articles on mounting basics look under the mounting section in Articles by Subject.
Additional information on all types of mounting is found in:
The Mounting and Laminating Handbook, Second Edition, 2002,
The Mounting And Laminating Handbook, Third Edition, 2008 and
Creative Mounting, Wrapping, And Laminating, 2000 will teach you everything you need to know about getting the most from your dry mount equipment and materials as an innovative frame designer.
All books are available from Designs Ink Publishing through this website.
Chris A Paschke, CPF GCF
Designs Ink Publishing
785 Tucker Road, Suite G-183
Tehachapi, CA 93561