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Posted: Thu 18 Feb, 2010 2:23 pm
by Ian Goodman
I had a cutomer bring in aratehr large framed image that had mould growth on the image as well a the back of the frame was mdf which has a black mouldy growth in the centre of the back of the job.

The image has been dry mounted onto this terrible medium MDF and is loose, the matt that is on this job has been dry mounted also making it impossible to be able to remove this matt as it has the worst case of overcuts I have ever seen on a job.

I would like to be able to remove this matt so that I can reheat the image in my Hot Press so as to flatten the image but because I cannot remove this matt I may not be able to do this.

However I do not give in that easy with a little thinking about this I can reheat this using the foam in the press it should be able to pressurise the image, so I wil try this tomorrow.

I am not a fan of MDF in framing it does have a place and that is not in framing.

In fact it should be banned totally no questions asked.

To those who say they are proud users of MDF you must be kidding.


Posted: Thu 18 Feb, 2010 2:31 pm
by Roboframer
I've removed mounts like this, well, down to the backing paper, by making deep scores and peeling the layers away. It can be a pain if it's old and brittle though.


Posted: Thu 18 Feb, 2010 3:42 pm
by stcstc
not sure i would want the mould in my heat press, wouldnt know what else it would get on


Posted: Thu 18 Feb, 2010 6:10 pm
by Bill Henry
I’ve ben faced with this problem a few times in the past. What I have done is cut a new mat with exactly the same dimensions as the existing one, and place the fallout of the new mat into the opening of the old one. This is then placed into the dry mount press. Mat board will transmit heat more efficiently than foam as well as giving you a more consistent pressure on the artwork.

As far as MDF is concerned, I’m not a big fan, but mold can grow anywhere. I’ve seen old frames with Foam Board backing stored in damp basements which made me want to call out the HazMat team.

Before you risk transferring the cruddy MDF into your dry mount press, wash the back of the MDF with a 5-10% solution of household bleach and water. It probably won’t remove all of the stain, but should kill most of the spores and stuff. In any event, you may need to sacrifice a few sheets of the silicone release paper to protect the platen and the felt pad in the press itself.


Posted: Mon 22 Mar, 2010 5:10 pm
by Art Surgeon
Everyone knows that picture restorer/conservators are shy and elusive creatures, but the mention of the shortcomings of MDF backboards by Ian Goodman has finally got me to stick my head above the parapet and join in, having kept to just reading the posts on this excellent forum for a few years. He is quite right in pointing out that the material acts as a magnet for damp and mould.
I often have framed watercolours and prints brought to me for urgent attention where the hideous multi-coloured mould has clearly been caused by severe damp penetration from the wall and straight through the MDF. Hardboard (Masonite) is usually not quite so bad.

Just how porous it is can be impressively demonstrated with the use of a powerful vacuum cleaner; Tear up a small piece of newspaper into tiny pieces. Hold a sheet of 2mm MDF upright. Switch on the cleaner and put the nozzle tightly to the board. Your bits of paper should now hold to the other side of the board, and drop off when you switch off the vacuum.
The same trick can be done with a few drops of water, which should be drawn through the board in seconds.

So I would say that MDF really is unsuitable for use on anything but the cheapest and cheerfullest end of the market, unless a waterproof barrier is put inside the frame. Melinex is ideal, or even good quality polythene is much better than nothing. This would cost pennies only, and would have the additional benefit of protecting the artwork from being contaminated by the rather unpleasant urea-formaldehyde fumes given off by the MDF.


Posted: Mon 22 Mar, 2010 11:22 pm
by framemaker
Welcome to the forum Andrew, its good to have your extensive experience here.


Posted: Tue 23 Mar, 2010 10:08 am
by John
Welcome to the forum Art Surgeon.

Thanks for that very useful information.

I have just conducted the vacuum cleaner experiment and can confirm that MDF really is that porous.

Never too old to learn. :)


Posted: Tue 23 Mar, 2010 11:10 pm
by Ultima Thule
As another rather silent member, and certainally no conservator, I would reiterate the failings of MDF. Despite my workshop being heated and dry I became aware of a damp smell around my store pile of backing offcuts last year. They were the usual mixture of 2mm hardboard, the various incarnatio ns of Corri-cor and Mdf,and some had ben lying around for months, if not a year or two. Upon closer examination the MDF nearly all hadthis odour, wheras the card and hardboard was taint free and did not appear to have gathered moisture. The result of this was that every bit of MDF in the shop was binned, not that I liked it anyway, and used it as little as possible; now not at all.


Posted: Wed 24 Mar, 2010 3:11 pm
by prospero
If I may chip in with a few observations......

I tried the vacuum cleaner test and yes, it does draw moisture into the board. I also tried it on a piece of Artbak and it does the same.

Tried another experiment:

Dripped water onto a piece of MDF and a piece of Artbak. After a few minutes the water had soaked into the Artbak and created a patch soggy enough to push my finger though. The surface of the MDF had started to break up and could be rubbed off, but the water didn't penetrate as far and I couldn't jab my finger though.

Conclusion? Well draw your own. :)


Sure. Mould will grow on MDF. It will grow on anything given the right conditions.


Has anyone any evidence that the fumes that MDF gives off does any damage to artwork? OK, you may not like the stuff but we are talking preservation issues here and not operator comfort. The thought occurs that as formaldehyde is widely used to preserve things, it actually aught to inhibit any bacterial action. Don't quote me on that.

Acid content.

Anyone actually measured this or has any technical info regarding? I'll venture to say that it is no worse than the average frame. If good mounting techniques are used, why should this be a problem?

Here's another experiment.....

Hold up a piece of MDF and stab it with a screwdriver. Then hold up a piece of Artbak and do likewise. You may say that's an extreme example. Who goes around stabbing frames? (Probably more people than climb inside frames with a hoover.)

Just for the record I do add a sheet of cellophane under MDF. I'd do the same if I used Artbak.

That's my fourpenneth. No offence intended or criticism implied. It's just that I feel it is unfair to highlight the possible shortcomings of one thing without doing the same with the alternatives.


Posted: Wed 24 Mar, 2010 7:52 pm
by mikeysaling
ok - if you have a frame 3 x 2 feet that is - full of medals what backing do you use ? mdf seems easiest but what else can you use? all other boards ive look at are a bit flimsy for this size! - this is a genuine question cause all this talk (negative) about mdf has got me thinking!



Posted: Wed 24 Mar, 2010 11:35 pm
by Ultima Thule
What I have used for backings this size, dependant on the weight of the contents etc., include 2mm hardboard, Art Bak,ply, fome board, as suitable. I find hard board more rigid than MDF for sizes such as these, and a barrier of some form is between the less savoury of these.


Posted: Wed 24 Mar, 2010 11:52 pm
by Roboframer
I'd say 3x2 ft isn't too big for a 5mm foam board back, as long as, or especially if, there is also a 4 ply under-mount.

All depends on what level you want to frame to - if it's a large cheap/easily replace-able/don't-give-a-stuff-about thing that is framed against the glass and probably dry-mounted why worry about MDF?

If it's a large valuable thing and you've mounted it front and back with the best there is and glazed it with UV glass, then there are indeed very high quality boards that are just as rigid as MDF if not more so - but they cost a packet.

Click here - scroll down for the 'double wall' stuff

Or even better!

Point is - stuff exists outside of our normal trade catalogues/publications - just a case of warranting it.


Posted: Thu 25 Mar, 2010 12:44 am
by mikeysaling
ok i'm interested in alternatives - what is as sturdy as mdf/hardboard 3 x 2 but to fit my standard 5mm inner frame rebate and allow turn buttons on back for removal. suggestions anyone

my schematic of frame
mike1.jpg (45.81 KiB) Viewed 15987 times


Posted: Thu 25 Mar, 2010 1:03 am
by Roboframer
I gave some alternatives and there are others too - but maybe they are more subject to crushing at the extremities, especially with frequent removal, or maybe some aren't - but most will cost far far more than MDF either way.


Posted: Thu 25 Mar, 2010 2:32 pm
by robbiez
I use 1 pallet of MDF a week @ 96p a sheet. There are no alternatives at that price and that do the same job.


Posted: Thu 25 Mar, 2010 9:31 pm
by Nigel Nobody
Roboframer wrote: All depends on what level you want to frame to - if it's a large cheap/easily replace-able/don't-give-a-stuff-about thing that is framed against the glass and probably dry-mounted why worry about MDF?
Spot on Robo!
Sheeesh, I haven't had a job like that since 1985! No wonder I have no use for MDF!


Posted: Thu 25 Mar, 2010 11:26 pm
by Dermot
Haven’t had or haven’t bothered to take a job that MDF could be used on……..the answer could make a big difference to what is implying.

I would find it extraordinary that a full service framing shop would not have had a call for MDF in a period of 25 years.


Posted: Fri 26 Mar, 2010 3:19 am
by Nigel Nobody
In my early days when I didn't know better, I used MDF as a backing. I lied about the 25 years. It's probably closer to 20 years.

Some of those old MDF backed frames have come in from time to time for a new mat, or a new glass and just seeing the consequences after many years is quite enough to make me resolve not to use this stuff in any frame, ever, even if all the other backings in the universe were not available!

I don't tend to get temporary, throw it away jobs. People must go elsewhere for those. They have plenty of choice. Most of the 'cheap' framers in the area use foamboard backings anyway. That's quite a step up from MDF IMHO!

Some of the posts on this topic have pointed out the disadvantages of MDF and I'm not going to re-iterate those.

There are other types of backing and I don't know of one that absorbs moisture and grows mould as much and as badly as MDF. Excluding all others reasons, that would be enough for me!

I don't want to get into another round of the same old arguments and the same old reasons why and why not! It's been done to death already!

It's not a matter of "having a call for mdf". People don't specify types of backing and even if they did, I wouldn't supply it, because I choose not to use it.
Plain old foamboard is not that much more costly to buy anyway!

Each framer runs his own business the way he wants, buys what he wants to buy and uses whatever he wants to use!


Posted: Fri 26 Mar, 2010 10:55 am
by Not your average framer
In most cases, unless you are a contract framer where price is more important than anything else, the cost of the backing board as part of a framing job is a trivial proportion of the overall price. I'm not sure that the cost arguement is normally a viable one.

Where extra rigidity is an important issue, I use CombCor from Brittania Mounts. It's 5mm thick, triple fluted, thick facing layers and very, very rigid indeed. If fact, I think it is more rigid than 2.5mm MDF. In the white faced version (the cheapest one) and when I last bought a box, it worked out at £2.65 + VAT per sheet.

I also stock 4mm Correx, 3mm / 5mm / 10mm foamboard, standard kraft core and Simons BACK 10.

The alternatives to MDF are just so much easier to work with.

P.S. If cheapness is the main issue how many of you have looked at the bulk prices for Simons BACK 01. I think that one weighs in at about £1.22 + VAT per sheet.


Posted: Fri 26 Mar, 2010 2:31 pm
by Art Surgeon
As Prospero's wild experimentations demonstrated so effectively, most other backboards can also get wet and soggy, so if the artwork is in any way important a "damp-proof course" of polythene or Melinex inside the frame is always advisable.
By the way, I wouldn't advise Cellophane for this as it isn't fully waterproof. (See Wikipedia.)
Thinks: I wonder why I'm saying all this and talking myself out of a job? After all, damp and spotty prints and watercolours are my bread and butter.