Need settings for press

[huguito]

I am trying to get the grip of where's the sweet spor of the used dry mounting press I go recently.

This question is for anyone using a dry press, for a sheet of fine art Matte like Epson hot press bright or Baryta paper like Ilford gold silk mounted on 4 ply matt board.

How hot do you set the press?
How long does it take to be up to temperature and ready from turning it on?
How long do you keep the print in it?
Do you let the pressed piece cool off just laying on a table or keep it pressed flat while it cools?

Thanks a lot, I have few of the test pieces come undone, maybe too cold or too short time, others blister the surface of glossy paper, maybe too hot.

Thanks again

Hugo

[BrianWJH]

Hi Hugo, give this link a try, there are many videos that may be of help.

Brian.

[datro]

I hesitate to give you my details, since you really need to test for your press, but here goes:

• Equipment:  Seal Commercial 210M press
• Temperature setting for my materials and my press:  Knob is 2/3rds between 200 and 250; this results in a max of 225 degrees according to the temperature dial after the pre-heat of the press in closed (not locked) position.  NOTE:  This setting was determined by testing using the Seal wax temperature strips.  You MUST do this in order to determine the proper temperature at the tissue/print for your setup. Colormount needs about 190-200 degrees.
• What I'm pressing (from bottom to top):  4-ply bottom board, 4-ply mount board with Colormount tissue tacked to print and board, 4-ply top board

Basic procedure:

• Pre-heat press (closed but not locked) for 20 minutes (you want the heating element to cycle at least once)
• While press heats up:  Clean all work surfaces, remove dust, setup tacking iron, trimmer, etc.
• Pre-dry bottom and top cover boards together  (1 min. in press, not locked)
• Pre-dry the print (30 sec. in press face down between cover boards, press not locked)
• Tack tissue to print, trim print/tissue to final size
• Pre-dry mount board (1 min. in press, not locked)
• Position print on mount board and tack tissue to board (tack two places on one end only)
• Assemble cover boards and mount board, press for 2:15 (24x29in. board) or 3:30 (29x36in. board).  Press the tacked end of the print first if you are pressing in sections.

NOTE:  Since my boards are larger than my press, I press in sections with about 25% overlap for each pass in the press (same for the pre-dry steps).

Cool the mounted print (face up) on a flat surface (2 min.) with a cover board on top and some weight on top of the cover board.  Inspect the print.  Test bonding at the print corners by slightly bending the board away from the print at the corners.

Dry mounting is part precision and lots of practice.  Once you have a working procedure, document it and follow it every time.  Use a timer to be precise about the times to ensure repeatability.  Calibrate your setup using the wax strips for the tissue and "sandwich" you plan to use in the press.  Don't skip the pre-dry steps; moisture in the materials is the enemy for dry mounting.  Keep in mind that board size affects how long you will need to press.  Generally speaking, it is better to give more time in the press rather than raising the temperature significantly to get the desired sweet spot. My procedure is bascially derived from Ansel's process as documented in his book "The Print".

I hope this will help to get you started.

[bill t.]

If you're getting both mounting failures from too little heat, and blistering from too much heat, then you might have a press with a broken thermostat.  Check out this thread...

http://www.luminous-landscape.com/forum/index.php?topic=85328.msg691470#msg691470

Or the failures may be due to not driving out the moisture from the print and backing, prior to mounting.

And I've got even more long-winded older posts, you can search if you like.

[huguito]

Thanks guys
Datro, can you tell me about those test strips you mentioned? Are they to calibrate the real temperature of the press against what the dial shows?   Can I use a thermometer sliding the tip in between the sheets that cover the print when in the press
Thanks again guys
Hugo

[datro]

The strips I have are called "Temperature Indicator Strips" and were made by Seal.  Each strip contains two small colored wax deposits on the strip.  One of the waxes melts at 200 degrees, the other at 210 degrees.  Using a test print on the same paper you normally use for printing, you put the strip inside a folded piece of release paper where you would normally put the mounting tissue, then adjust your press temperature and/or time in the press until the 200 melts but the 210 does not. Ideally you would do this in several locations under the press to make sure you are getting even temperature throughout the platen area. It's a sacrificial process; once you have used a strip it cannot be used again.  The (very old) box I have came with 50 of these strips.

Unfortunately Seal has I believe gone out of business; and while the presses, parts, and other accessories are still sold under the D&K brand name (see B&H web site), it does not appear that these particular strips are made anymore. I'd suggest you Google to find something similar.  Talas has something called Thermopapers that would probably do the trick.  The key is to first determine what is your target temperature for the mounting tissue you plan to use, then obtain an appropriate indicator in that temperature range.

[bill t.]

http://www.harborfreight.com/non-contact-pocket-thermometer-93983.html

If it doesn't fit under your platen, then press a stack of scrap, and measure the surface temp as you slide the artwork package out.  Temperature drop fast, you gotta be quick like a bunny.  Be sure to check for uneven temperatures across the platen, that means you have a dying heat element.

[huguito]

I am currently pressing in between two sheets of matte paper. Never had those slick to the touch release sheets.
I was told by the person that sold me the press that any thick paper will do, not sure if they are a MUST item.
Is that OK or should I order release sheets to sandwich the prints in between them while I press?
Hugo

[bill t.]

Use a relatively thin piece of paper for the cover sheet.  It will take the heat too long to penetrate a thick cover sheet.  The best cover sheets are about 20 mils thick, about the thickness of heavy fine art paper.  Cheap, thin "poster board" from the neighborhood drugstore is about right.  Release paper cover sheets are a waste of time and money, unless you want to leave un-trimmed tissue visible past the edge of the print which is why we have release papers.

For Colormount tissue, it is IMPERATIVE that you use the thinnest possible cover sheet!  Colormount requires an extremely fast temperature rise to give good bonds, that will take too long with a thick cover sheet.  Leaned that the hard way.  Most dry mounting tissues are less critical.

The only exception is if you are mounting a large piece in sections.  Then you want a fairly thick cover sheet to keep the edge of the platen from creating a visible line in the mounted print.  Then you need to increase pressing times by about a minute.

[huguito]

Thanks Bill
I am using sheets of Epson matte paper as cover sheets, is that too thick?
Hugo

[Paul Ozzello]

bill t and datro,

Do you have any other recommendations for mounting really large prints in sections to avoid getting lines ?

[datro]

I regularly dry mount in sections since most of my finished prints are on boards of 24x29 or 29x36 and I'm using the Commercial 201M press with a platen size of 18.5 x 23 inches.  I would say the key is to use cover boards (4ply in my case for both top and bottom) which match the size of the mount board with the print.  For each of my mount sizes, I have a dedicated pair of cover boards which I keep meticulously clean.  Since they are the same size as the board I'm mounting with the print, there is no place in the "sandwich" where a top or bottom edge could press into the mount board and leave a noticeable line.

Also, it is really important to make sure the press has been properly adjusted for the thickness of the sandwich that you plan to use.  Otherwise when locked you might be putting too much (or too little) pressure to get a good bond without other problems.  The owners manual for my Seal press describes an easy procedure for this.  This site also describes the procedure (I have no connection with that site).

Dave