Thread: MDF and Safety

Originally Posted by Arry

So what type of wood do most of you use or does it really depend on what you are doing etc.

It really depends on what you are doing. At a high level, if your making fine furniture for SWMBO you will probably be choosing timber based on how it looks finished, how stable it is, how strong it is, what different natural colours complement each other etc etc. For less vsisble and Aesthetic applications such as shelves or wortops in the shed you will look at plys, KD hardwood from bunnies, etc. At a more detailed level the conversation gets endless.

Originally Posted by Arry

One of the guys here reckons he uses Jarrah for shelving in his garage but that sounds overkill to me, especially since I presume Jarrah would be far more expensive than something like PLY.

I'd love to have enough Jarrah to make workshop shelves out of it but if I did, I would probably use it for something else. It's quite likely that our WA friends would use Jarrah for some applications we wouldn't just because of availability although that's becoming less of an argument now though due to increasing scarcity of timbers generally, but when I lived there we made pergola's out of it.

Hi Arry:

I use MDF when I lay up veneer. I wear a mask, but I try to wear a mask whenever I'm cutting and on heavy cut days I wear it through-out the day, and that goes for all materials I cut, not just MDF.

I use all materials...........although I'm not from around the corner, that "bloke" who said nobody is buying plywood anymore.....BIG question mark there.

Back to MDF....I find it to be an excellent material in its proper use. back in the 80's, lacquer furniture with all kinds of faux finishes were hot and most (90%)of that lacquer work was done on MDF. We would lay-up Zebra wood in a race track oval shape and bullnose the edge in black lacquer then clear coat the entire table all done on MDF.

It's a good material when use properly.

Neil

Originally Posted by rayintheuk

WATCH endorsed the conclusion of the hazard assessment that there is no evidence that the ill-health effects associated with exposure arising from the machining of MDF are different from those associated with similar exposure arising from machining other forms of wood.

There is some evidence for more frequent reporting of respiratory symptoms in workers receiving exposures arising from machining MDF compared to other forms of wood or wood products.

Given that all wood dust is now regarded as carcinogenic, I think MDF should be treated as you would asbestos.

Talking to a guy who got mesothelioma from professional asbestos removal work he observed that one of the euro countries (Holland I think) had banned MDF because of how resin dust in the lungs behaves.

Originally Posted by BrettC

Maybe the Bunnies guy was referring to the ludicrous overpricing of ply that we are forced to fork out for in this country...

Here-here!!
.. ever tried to buy a piece of high-quality 9 or 12 ply with a finished face....not in any of the walk-in purveyors in my neck of the woods. Very frustrating.
I see more hopeless results on stuff made with MDF than with ply..it's good at what it's good at, but hopeless for almost everything else.

The nearest sheet goods supplier to me charges about 20 bucks to deliver which is cheaper in time and money than I could pick up. Then 19 mm 2.4 x 1.2 construction grade ply c. $70, Hoop pine c. $150.

There’s a lot of people here that spend a fair amount of money on tools, dust control should be just part of that expenditure.

I cut up a lot of MDF boards for speaker projects and I’m slightly asthmatic so my body quickly tells me when there is the slightest amount of dust in the air. All larger machines are ducted to the DE – outside. All smaller power tools are connected to the vac when ever possible, I wear a filtered mask during all cutting and where I can not extract I wear a ventilator. Usually I also have an industrial fan blowing over cutting surface to the outside.

I keep both roller doors open to get dust out of the shed. Even with all that I can still “feel” fine dust in the shed at the end of the day when I close up. So I turn on the dust filter unit for a couple of hours and if I return later I can feel the cleaner air.

What I am using at present:
3/4" ply for a mobile bench for my morticing machine.
16mm veneered MDF for a cabinet for the plasma and home theatre
Tas Oak and Karri for the frame (external) for the above.
3-6mm MDF for templates
Ply for some shelving in the tack room.
Really it's horses for courses but MDF has a shocking rate of sag and I never use it for long runs without cleats or some sort of bracing.

I don't know about other places but the Bunnings in Tamworth have racks of ply from three ply right up to 25mm thick ply in all types. e.g. Marine, interior, exterior, form ply, bracing ply etc.in small sizes for the hobbiest up to 1800 x 900, 1800 x 1200 and 2400 x 1200. They arn't cheap but they do have it.

I recently used MDF as a tabletop for a kids table. I used pine for the rails and legs and just pocket holed the slab of MDF on top(After routing the corners round and a decorative finish all round.) At 16mm there is no sag, the top is perfectly flat and smooth, took a coat of paint well and the routed edge looks terrific. All this for about $20.
It is a good choice in certain circumstances..

I was given a fold up table tennis table with a water damaged top.

One sheet of MDF some paint and 5yrs later still getting used

The special paint cost more than the MDF sheet.

Heres something to think about regarding MDF.

I began using it years ago as both a cabinetmaker and a wood machinist, long before anyone knew anything about the bad side of it.

After many years I found myself getting a rash anywhere sweat occured, very painfull at times. Ended up going to a specialist doctor to find a cure for the problem.

The cure was simply stay away from MDF, the resins in the dust become an irritant and when sweat was added, it caused an extremely bad reaction which resulted in a very bad burning sensation. I eventually gave the trade away when the reaction became so bad that my forehead came out in blisters.

I'd had no contact with MDF for about 14 years when I started a new job in a kitchen manufacturer about 18 months ago. I remember reading the warning labels on the packs of MDF sitting in the factory, had never seen anything like that years ago. I worked out front in the sales area and it took about 2 months for the allergy to take effect again, red raw rash across the forehead. I gave it away about 4 months later, just wasnt worth it.

Anyway, just my 2 cents worth on the subject,

Ross.

Arry,

In 2003 I lost my sense of smell for weeks after extensive working with MDF outside but without a mask. All food tasted like mouldy porridge and beer was so bad I could not drink it.

FWIW:from http://www.alpinemdf.com.au/documents/wooddust.pdf it has a extract from the following article ; KY Chung et al (Ann. Occup. Hygiene Vol 44, No 6 pp 455- 466, 2000) A study on dust emission, particle size distribution.

The AlpineMDF company article states.

The results show in general, the dust generated by machining MDF and Particleboard is comparable in terms of particle size distribution and morphology with dust generated by similarly machining solid hardwood or softwood.

Amount of Dust
The quantity of dust generated by sanding is higher for MDF compared with sanding either hardwood or softwood. However, for sawing there is no significant difference between MDF, other panel products and natural woods in terms of quantity of dust generated.

The Chung article has a couple of interesting diagrams unfortunately they are not all for the same activity. For comparative purposes I combined a couple onto the one diagram.

The Black curve is the particle size distribution for the sanding of pine using 80 Grit paper - as you go to finer grits the curve moves to the left. The red line is for the sawing of Oak. Hardwoods (especially our Aussie varieties) always generate a lot of fines when both sanding and sawing. MDF is supposedlysomewhere between the two.

The blue line represents the 1 micron line - particles less than one micron cannot be seen and so do not readily show up on finished surfaces. In terms of total volume they represent much less than 1% of the total dust, but there are still a lot of them and they can penetrate a long way down into the lungs (fortunately most also blow out again) hence they are the ones most dangerous to your health. Standard carbatec type room filters only filter 85% of particles at 1 micron and are even less efficient at lower particle sizes. The Green line represents the 5 micron or needlefelt filter line. The Brown line represents DC and most shop vacs.

What this is clearly telling me is that there is nothing really available except mask type filters to filter wood dust in WW shops. Sure you can wear a fancy mask but you then have to wear it continually for days after generating the dust.

So In case I annoy anyone I'll say it in a whisper , the simplest solution is to put your DC and shop vac air exits outside

When you read US and UK magazines they have products in Home Depot they call plywood that are flat, dimensionally stable and look good. They have Birchply, cherry and oak faced are common. Wish we had some - try to buy birchply in Australia or even B/C plywood is a joke. The best they have at most suppliers barely qualifies as the C/D grade it is supposed to be full of knots, voids and other faults. And Flat!- you must be dreamin.

And if you want any decent face veneer you have to find a specialty supplier and even then it is quicker to bite the bullet and accept veneered MDF. Quality Ply in on the endangered species list in this country.