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Question Anyone have problems with mount core and need to counter mount.

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Joe B

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Last week - but my fault. I was using release board between the mount and platen. When using a release board you need to add another minute or two to get the adhesive to activate properly.
 

Nikodeumus

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Are you using a mechanical or vacuum press?

I use a mechanical Seal press.
For larger items/posters there can sometimes be a fair bit of bowing.
Here's what I do to minimize (not completely eliminate) bowing on larger items:
  • use the lowest temperature I can, while still achieving a good bond.
  • whenever possible, put the paper item between two slips of kraft paper and put it under the press for 15 seconds or so.
    • this is recommended to remove any moisture that may be in the paper item, plus I like to take out any curl in the paper item before mounting
    • I don't know if it really matters, but the reasoning seems sound to me: a curled item will want to "pull up" a bit more, because of the difference of the bonded side of the Mountcor reacting to the activated glue differently than the non glued side. It also really depends on the nature of the material the item is made from.
  • do only one "bite" of the press, then immediately put under weight covering the entire item, not just the heated section
    • layers over the mounted item on Mountcor: a coated slip sheet, then foam board, then weights
    • have all items laid out and ready to put in place, so the Mountcor doesn't cool down at all before being weighted
  • let it sit for at least 5 mins or more
  • repeat steps above for the next bite, etc.
  • after all sections have been bonded, if it still has some bowing, I will warm the entire piece (not under pressure) and re-weight for 10-15 mins.
Sometimes even this won't get rid of all bowing.

Is this for an item to go into a frame? Or for an unframed display?
I usually caution my customers that Mountor is not always the best choice for non-framed displays. Simply because of the nature of this problem of bowing.
I have never used it, but I think Gatorboard is a better (stiffer) mounting material, but it doesn't have pre-applied glue, like Mountcor.


When using a release board you need to add another minute or two to get the adhesive to activate properly.
I pre-warm my release board.
While preparing the item on the Mountcor, the press is warming up with the release board under the platen.
All toasty and ready to go.
 

Jim Miller

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I'm pretty sure MountCor still has a thermosetting adhesive, which means that it can be activated by heat only once. It's essential to get it right the first time, since re-heating would not increase the bond. Also, reversing the mount requires a solvent bath.

If you want a more forgiving dry mounting board, Kool Tack has a thermoplastic adhesive, which means that it can be reactivated by subsequent applications of heat. So, you could put it back into the press if the bond didn't hold the first time. Also, you can reverse it using heat.
 

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Jim, I have used cut offs from used Mountcor and reused them with the same results as a fresh board. You can't reactivate and release the bond on a mounted item, so this falls somewhere between those two definitions. I use a fair amount of the product and find that new and used act pretty much the same.
All of what I use it on is sacrificial art. Displayed for a few years, then replaced.
I have used the Kool Tack and it works quite well, but I really like the individual release sheets provided with each sheet of Mountcor.
This is not a product endorsement, just MHO.
 
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tombe

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I am using a vacuum/heat mount press. This was my first post so kept it short because I was having trouble posting. When I say prints I am referring to "poster quality ones". I wrecked the surface sheen of a print that I am replacing and thought mountcore might work. A cheap digital print I guess. Original one I used "fusion" and a cons board backing. Jim, I did not know that about mount core and have used kool tack a lot. I have used very little mountcore. I started using fusion with reg. or rag artcare foam core for more textured prints and then regular prints. what do others use for these cheaper digital poster like prints and some photos whe dry mountig. Enough for this reply. Jim this is Tom Benish of Benish Studios nad have taiked to you in the past.
 

tombe

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Are you using a mechanical or vacuum press?

I use a mechanical Seal press.
For larger items/posters there can sometimes be a fair bit of bowing.
Here's what I do to minimize (not completely eliminate) bowing on larger items:
  • use the lowest temperature I can, while still achieving a good bond.
  • whenever possible, put the paper item between two slips of kraft paper and put it under the press for 15 seconds or so.
    • this is recommended to remove any moisture that may be in the paper item, plus I like to take out any curl in the paper item before mounting
    • I don't know if it really matters, but the reasoning seems sound to me: a curled item will want to "pull up" a bit more, because of the difference of the bonded side of the Mountcor reacting to the activated glue differently than the non glued side. It also really depends on the nature of the material the item is made from.
  • do only one "bite" of the press, then immediately put under weight covering the entire item, not just the heated section
    • layers over the mounted item on Mountcor: a coated slip sheet, then foam board, then weights
    • have all items laid out and ready to put in place, so the Mountcor doesn't cool down at all before being weighted
  • let it sit for at least 5 mins or more
  • repeat steps above for the next bite, etc.
  • after all sections have been bonded, if it still has some bowing, I will warm the entire piece (not under pressure) and re-weight for 10-15 mins.
Sometimes even this won't get rid of all bowing.

Is this for an item to go into a frame? Or for an unframed display?
I usually caution my customers that Mountor is not always the best choice for non-framed displays. Simply because of the nature of this problem of bowing.
I have never used it, but I think Gatorboard is a better (stiffer) mounting material, but it doesn't have pre-applied glue, like Mountcor.



I pre-warm my release board.
While preparing the item on the Mountcor, the press is warming up with the release board under the platen.
All toasty and ready to go.
I will be framing. Only about a 16x20 poster quality print but wrecked surface of one I am replacing and trying to make sure of things. Will also be putting a thin mat per cust. request. A digital print I think and was thinking of lower temp then 160 I was using with fusion. Can check my other reply.
 

Nikodeumus

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I wrecked the surface sheen of a print that I am replacing and thought mountcore might work.
Many years ago I had a similar thing happen to a 12x18 cheap cheap cheap poster print a customer ordered online.
A lot of the ink lifted right off the poster when heated in the press.
That had nothing to do with the kind of mounting materials used.
It was the terrible quality print. The paper was a weird semi-gloss, and the ink simply hadn't absorbed (or adhered?) to the paper.
I also had to purchase a replacement.
Also, being a non-conservation job, we elected to do the mount with a self-adhesive mounting board with the replacement, as heat was clearly an issue.
 
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tombe

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Shayla

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We almost always use Mount Cor for such things. (Although I sure was happy, when I accidentally mounted a Post-It under something, that I'd used KoolTack).

When you remove the mounted art from the press, what do you do with it? Lay it flat? If so, with or without weights? Or do you stand it up, leaning against something?
 

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The original Successories posters were printed using a wax base medium and dry mounting them was certain disaster. They were easy enough to replace, but they made a mess.
There are still some posters being printed using thermal technology (Xerography) and are susceptible to darkening when dry mounted.
Most of the ink jet (Gilcee) work is fine with either KoolTack or Mount Cor low temperature bonds (135F +/-).
 

tombe

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I'm pretty sure MountCor still has a thermosetting adhesive, which means that it can be activated by heat only once. It's essential to get it right the first time, since re-heating would not increase the bond. Also, reversing the mount requires a solvent bath.

If you want a more forgiving dry mounting board, Kool Tack has a thermoplastic adhesive, which means that it can be reactivated by subsequent applications of heat. So, you could put it back into the press if the bond didn't hold the first time. Also, you can reverse it using heat.
I was thinking of mountcore because of lower temp and worried about affecting the surface inks of the print/poster that I think is digital. Not sure how good a digital as they also sell a giclee version.
 
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tombe

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We almost always use Mount Cor for such things. (Although I sure was happy, when I accidentally mounted a Post-It under something, that I'd used KoolTack).

When you remove the mounted art from the press, what do you do with it? Lay it flat? If so, with or without weights? Or do you stand it up, leaning against something?
I lay on a flat surface of usually smooth mat board for most, face and back, with plate glass weight and leave for awhile. Some I leave under weight till I use. Sometimes leave release paper on and sometimes not. By the wa,y do you usually use regular release paper? usually don't have a problem with. I am more concerned about wrecking the finish of this kind of poster/print then buckeling.
 

Jim Miller

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Jim, I have used cut offs from used Mountcor and reused them with the same results as a fresh board. You can't reactivate and release the bond on a mounted item, so this falls somewhere between those two definitions. I use a fair amount of the product and find that new and used act pretty much the same.
Hmm. Thanks for that information, Wally. Maybe something has changed from the original adhesive. It would be interesting to know why it can be reactivated before actual mounting, but not afterward.

...I really like the individual release sheets provided with each sheet of Mountcor.
Another benefit of MountCor is that it would not be affected by high heat from some ambient condition. I once heard of Kool Tack releasing after exposure to high heat in a sun-drenched vehicle, but that would not happen with MountCor.

Both MountCor and Kool Tack are good products and suitable for most dry mounting applications, but I believe it's important to know and understand the differences between them. They are not exactly interchangeable.
 

David L. Brown

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We have been using MountCor for larger posters and prints and just sealing with a moderately hot iron. I have a Seal Masterpiece hot press that I use for pieces up to about 20x30, but don't like using the "bite" method for larger pieces. Using the MountCor release paper, I just lightly swirl the iron over the print until it is nice and flat. We've used this method to mount pieces up to 40x60 with no problems. We got a point-and-click temperature gauge to test the iron and know which setting to use to make it about 130 degrees. The fact that MountCor is low temp makes this practical. My hot press is usually set for about 190 degrees to bond smaller pieces with TechMount.
 

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I too have used a hand iron to mount to Mount Cor, but mostly for things that would be challenging just tossing it in the Vacuum press.
I just did a plat map of my home town that was printed in 1972, neatly folded and stored since. The fold line caused concerns about getting it flat, but I used the hand iron working from the center outward on top of the supplied release paper and was able to flatten the piece very nicely.
I still put it into the press and ran it through a cycle at 140F to make sure the bond was somewhat even. There was no getting rid of the crease lines, but the piece is otherwise perfectly flat.
IMG_0450.jpg
 

Nikodeumus

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I have only used an iron for very small items with Mountcor.
I was afraid that uneven temp. & pressure might not make a good bond on larger items.
Good to know others have had success.
I'll give it a test with one of my own projects. :thumbsup:
 
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Shayla

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I lay on a flat surface of usually smooth mat board for most, face and back, with plate glass weight and leave for awhile. Some I leave under weight till I use. Sometimes leave release paper on and sometimes not. By the wa,y do you usually use regular release paper? usually don't have a problem with. I am more concerned about wrecking the finish of this kind of poster/print then buckeling.
I still use a release paper over it. Used to use a release board, but haven't in a few years.

Another nice feature of MountCor is that it has tiny holes all through it. (Maybe every 1/2", or so.) Really helps to prevent bubbling.

The only problem I've had was a few years ago, when someone brought in a print from a local sign maker. I didn't realize it was basically a giant sticker, with a peel off back. It had also been coated with something. It mounted fine, but the finish dappled a bit. Ever since, I've told people who bring in prints with coatings about the risk that it could do that. This has only happened a few times, and tended to be with small prints on canvas that didn't have enough to stretch. They didn't want to add Beva, either. We ended up cold mounting to another substrate with acrylic gel medium and weights, and it worked well. But in general, any simple, postery thing gets Mount Cor. That said, KoolTack is great, and as long as the printing medium can take the heat, it's a fine option. And, as you've used it before, you likely know that their adhesive can come on different substrates.
 

David L. Brown

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I used to have a large vacuum hot press and miss it. But the MountCor is very impressive. The key to using an iron is to get the temperature right, keep it moving, and work from the center out. The iron slides over the release paper very smoothly, may be coated with Teflon or something. I did two large pieces yesterday, a poster and a map, and both worked fast and easily with the iron. Tip: Do not use the steam function of the iron. ;)
 

David L. Brown

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Here is a photo of my business partner with a print we made and mounted with MountCor. Double mat using black yellow core and a massive 40x60 L-J frame. that we cut and joined IMG_2208.jpg This is a personal photo he made and is hanging in our gallery, which we use as a display of our framing work. IMG_2208.jpg
 

tombe

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I still use a release paper over it. Used to use a release board, but haven't in a few years.

Another nice feature of MountCor is that it has tiny holes all through it. (Maybe every 1/2", or so.) Really helps to prevent bubbling.

The only problem I've had was a few years ago, when someone brought in a print from a local sign maker. I didn't realize it was basically a giant sticker, with a peel off back. It had also been coated with something. It mounted fine, but the finish dappled a bit. Ever since, I've told people who bring in prints with coatings about the risk that it could do that. This has only happened a few times, and tended to be with small prints on canvas that didn't have enough to stretch. They didn't want to add Beva, either. We ended up cold mounting to another substrate with acrylic gel medium and weights, and it worked well. But in general, any simple, postery thing gets Mount Cor. That said, KoolTack is great, and as long as the printing medium can take the heat, it's a fine option. And, as you've used it before, you likely know that their adhesive can come on different substrates.
The release material on the mountcore is a huge plus and shiny smooth. Regular release paper is good on many things but I have to use care that there is no crinkles or other things on it from using more then once. I use "fusion" on somethings and have to make sure nothing is left behind especially the blue type of release paper but not so much the other. I also used the board for awhile and haven't lately for some reason. May get out again and see why.
 
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wpfay

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I was thinking of mountcore because of lower temp and worried about affecting the surface inks of the print/poster that I think is digital. Not sure how good a digital as they also sell a giclee version.
Most printing for our industry these days is pigmented ink with ink-jet technology. Giclee is just a fancy word for ink-jet. They are all digital technologies.
The inks are susceptible to color shift at higher temperatures, but the lower bonding point of both options being discussed foregoes that issue.
 

Nikodeumus

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Giclee is just a fancy word for ink-jet.
I'm so glad you said that Wally.
There are too many artist/photographers throwing the term "Giclee" around without really understanding what it means, what it was originally, and where the print world is now.
They are focusing on the method of inkjet printing more than on the type and quality of the paper and inks being used.
But that's way off-topic for this thread, no need for a FrankenThread here, it's been discussed plenty already.
 
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