Along with myself, there are quite a few members joining who are new to CNC Milling and Turning and because of its overall strength and cheapness, MDF (Medium Density Fibre) Is a popular choice of material for building low end CNC Machines.   Myself I have used it exclusively for making hull formers for the scale model ships I build and one of the reasons I am building a CNC is tocut out these formers more accurately and easier with CNC mill.

Unfortunately you will never find warnings in timber stores about the hazards of MDF, contained in the toxic material used to bond the fibres into those innocent looking sheets.

Cutting and Sanding MDF in and by any form is extremely hazardous whether by hand or machine and at all times a quality facial mask with a replaceable filter should always be used.  In fact when ever cutting or machining any kind of material that raises fine dust should also be treated with precaution.

Similarly, you should always wear full wrap around glasses, do not rely on your prescription glasses, often today's fashions do not offer 100% protection.

I have deliberately avoided going into the chemical analysis of the compounds used as they vary from country to country - check on-line!

Have a great and safe day.
Cheers Dave.

Good information Dave - thanks for drawing our attention to matters of safety.

Tweakie.

Good information Dave - thanks for drawing out attention to matters of safety.

Tweakie.

Technically, most countries use Urea/Formalhyde, which are carcinogenic.  The same warning goes for plywood and chipboard.
Australia has introduced low level toxin resins.  However officially there are very strict rules about the sale/use/display of these products, but I have yet to see them practiced at any of the the timber/hardware outlets.
However the Australian Timber and Allied Industries Union  have a set of rules which must be obeyed by its members.  So I guess in the actual industry those guidelines are followed.

In the UK many of us (in particular those using lasers for cutting MDF) have switched to using the brand ‘Medite’ – the particle dust is still toxic and precautions still have to be taken, but at least it does not contain the dreaded  formaldehyde. Is Medite available down under ??

Going a bit off topic and just out of curiosity, are your MDF hull formers removed after the hull has been constructed or do they remain in place in the completed ship ??

Tweakie.

Not sure about the Medite, have not come across it.

 The formers remain inside the hull, the only ones exposed are in the open part of the hull where the electronics are, these are cut back to give maximum space inside.  The hull skin is on 0.7mm 3ply! very thin.  I actually  "plated" the hull of my HMS Loch Killisport to create the original "look" instead of using a full length sheet and "wrapping" it around the formers  as in my HMS Manchester. (That's why it took a year working on it every day!)

However before the the decking is added the entire hull inside is given a fibreglass resin wash which not only seals the MDF &  ply/joints inside but makes it entirely waterproof.  The outer hull is them primed, undercoated and finished in a matt standard Admiralty Atlantic grey.  I have found acrylic paint applied with an airbrush gives a nice finish.  The only time water may get inside is when it rains, but then its very minimal.

Dave

Excuse my typo on the spelling of formaldehyde!