unsticking mounts from paintings

[Mary Lever]

Hi
I have been given two very old watercolours to remount. The problem I have is that the mount has been glued onto the card on which the watercolour has been painted. I'm worried that if I try and gently peel it off, it may tear the painting. Does anyone know any tips for removing the mount from the picture?

[markw]

The mount will have been stuck down with a starch paste - it goes rock hard with age and is very difficult to remove. The method i use is to gently ease away the inside edge of the mount away from the artwork - or the backing board that the artwork is attached to. My prefferred tool is a plastic burnishing bone, but a scalpel handle works, or even the handle of a spoon - anything that will apply gentle pressure. The glue was often applied away from the inside edge so attacking it in this direction often works. Make sure that you protect the artwork by placing a piece of paper between it and the tool you are using.

you will normally find that the mount will ease away. You need to take real care that the mount doesnt pull and tear the artwork - gentle patient persistence will do it. If you are replacing the mount onto the artboard then scraping away the remaining glue residue will allow the new mount to sit flat.

If I think a mount wont come off then I would advise the customer that it needs to be removed by a paper conservator - I have had work in that was just too fragile to even attempt removal. in some cases the work was of little value and cutting the work out of the mount with a scalpel then remounting with the loss of a little of the original work can be suggested. If I think the removal of a mount is going to be a problem then I always like to explore the possibilities with the customer - no great suprises on either side that way.

[Mary Lever]

Wow! Thanks Mark for such a prompt and full reply on a Bank Holiday Sunday! The mount seems be stuck fast on the inside edge. I've only attempted to to peel it away on one of the four sides (before I posted this e-mail) right up to where it touches the painting and that is where I am nervous of proceeding further as it looks as though it could tear! I'll have a look at the other one and see whether it is stuck less fast and whether your method may work. Thanks for the advice.

[prospero]

I get a lot of these. Sometimes they are glued with the good old animal glue that was cooked up in a double boiler. You can tell it as it looks like hard toffee. I find an artists' pallete knife is the best tool. Slide in from the outside as far as it will go and give a twist. Then work round a little at a time. You have to be very careful not to run a tear into the painting itself. Try and tear it away from the old mount rather than the painting. Once you have it seperated, use a pair of tweezers to pull away any remaining bits of paper from the mount. There will be glue residue still on the painting. Removing this is an expert job. Best to leave it be and cover it with the new mount than risk chewing up the paper and making it unrestorable at a future time.

[Not your average framer]

I also get a lot of these. Your first move should be to determine how securely it has been stuck, where it has been stuck and what it has been stuck with. Quite often these can been carefully eased apart as previously described by Mark W and Prospero, but sometimes they can be too well stuck to just ease apart and these need another treatment.

In these difficult cases, I have found that it is often possible to peel away the layers of the mountboard in stages until you either get down to the layer of glue or the rear facing paper which is retained by the glue. After this you have to assess what kind of glue you are dealing with.

If it is an animal type glue, it may have become fragile with age and may be futher weaked by manipulation, with or without the introduction of exposure to low temperature, or as a last resort it may be removed by carefully controlled application of heat from behing the painting and it's backing, then gently peeling away of the remaining layer of paper while the glue is still soften with the heat.

This is not something to do with a hot air heat gun! Don't even think about it! A lot of us have done so and got away with it, but there are risks in doing so. If you are gonna be professional, then you won't take risks and you will find a safer, controllable method.

I use a variable temperature hot plate and a digital thermometer so I can see what is happening. Too much heat and you will end up with a horrible mess, but get the temperature just right and it will peel away very cleanly.

These type of glues melt at around 65 degrees centigrade, but there will be a temperature gradient through the thickness of the board on which the painting is mounted, so a little extra may be required.

The clever trick is too move the painting across the hot plate and as the heat starts to soften the side of the glue in contact with the painting to ease it away before the heat softens all the way through the glue. This means that a larger amount of the glue will remain fixed to the paper as you peel it away. Very little force is required to peel the paper away if the temperature is just right.

If it's has been stuck with a starch based paste then strips of wet blotting paper strategically placed will allow the paste to be softened to permit the remaining mount paper layer to be peeled away. Again if the paste has been softened by becoming wet enough then only minimum force should be required to remove the remaining paper.

Lion used to do an electric hot plate and may still do so, I think mine came from Argos. They are surprisingly useful things to have in your workshop.

[Roboframer]

Are you sure they are painted on a board and not on good quality paper which is STUCK to a board? Don't suppose you'll know until you remove the mounts.

But I'm guessing preservation is not an issue (if it is then I'd recommend a conservator, both to remove the mounts and also to remove the paper from the board and treat it - or just clean and treat it if it is painted on a board) and you just don't want the new mounts to be raised above the image by the old mounts or to cover any more of the image than the old mounts do - so they have to go.

If that's the case you can maybe peel layers of the old mounts away until you are left with just the last 'ply' - you'd still have to mount juuuuuuuust over that, but that would also cover some of any acid burn from the bevel, and if the signature is still fully visible, this method, which I have used, may be a go-er.

Have a look, from the edge of the thing, at the thickness of the mount, chances are it's about the same as what we use today and made in the same way, from 'plys' of board stuck together.

Adjust the blade depth on your mountcutter to score almost through the mount - you can practice about 5mm in from the outside edge. Once you have the depth right, make a score, again about 5mm in from an outside edge, but along its whole length. Then see if you can peel that strip away, layer by layer, if so, remove the margin guide and place the mount under the cutting bar (with the artwork masked with a mountboard offcut just in case) to make a cut from the inside corner of the aperture to the outside corner of the mount and cut - aim to start the cut JUST at the top of the bevel.

Repeat on the other 3 corners and then start peeling layers of board away from the inside out.

If the layers don't come away evenly then you can make vertical scores every 3" or so.

Keep going until you are down to a thickness, hopefully the very last ply, that won't result in the new mount being raised away from the artwork.

[Mary Lever]

Thanks very much for all your advice. The painting is in fact painted directly onto board and the window mount comes almost exactly up to the edge of the painting. I'd never thought of peeling away layers of the mount...thanks for the idea. I had vaguely thought of a steam iron but that did seem a rather ham-fisted, dangerous one to try out. One tme before I did in fact put the mount over the previous one and it did not give an unattractive 3D effect....but obviously did not cure the problem of an aciidic mount against the picture.
By the way, why does everyone have a pseudonym on the forum? Am I the only one who has not concealed their identity??!!!! Thanks to everyone for their advice.

[prospero]

No reason you can't use your own name Mary. This board has a relatively small membership. Some places have 10000's of members and having nicknames makes it easier to distinguish people with similar real names.

And it's a bit of fun.

[Dermot]

My name is Dermot......yep that's my real name.

[Mary Lever]

Just to say I've finally managed to get the mounts of the watercolours so thanks for all the advice. The painting is on paper and then stuck to another piece of board. Is it accetable to leave the paper on the board as to take it off would definitely be a paper conservator's job? I would obviously tell the client that and leave it up to him if he wants to pay the extra amount to have the job done professionally.

[markw]

Always consult with your customer. give them the choice - conservator - or your solution. You could mount over the top - but if too much of the previous mount is left behind this might cause problems. You could cut away the excess board - then replace it with strips of new board to build up the back. Obviously don't cut away without your customers permission.

[prospero]

Best to leave it be unless it shows signs of separation in localised areas. Some will completely come off with very little persuasion. But most of the time getting them off involves immersion and this is something best left to an experienced restorer. If the painting is of value it would be worth at least getting a restorer to look at it.
If it's of no particular value, I usually trim the board down to just outside the paper area. Line it up in the mount and flip it over without disturbing the alignment. Then stick scrap strips of mountboard to the mount to fill the gap between the painting and outside edge of the mount. Not to tight against the painting. This nicely holds it in place and makes everything level at the back. Few tabs of tape across the corners will hold it. SA tape doesn't stick too well to old board, but you only need to hold it in place long enough to assemble the frame. After that the mb strips will hold it.

** Great Minds think alike Mark.

[Mary Lever]

Thanks for that. Just seen the client and he is happy for watercolour to remain stuck on board. The window mount came off very cleanly in the end so new mount will be able to lie flat against the painting and look good. I guess just replacing the window mount and acidic wood used as backing will improve its conservation qualities tho it obvously would have been good to have brought the whole frame up to conservation level as he evidently greatly values the watercolours.