Woodwork 101

[Wozy68]

Tony Angelino said:

Wozy68 said:

Just remember ..... if your going to paint the MDF and especially so if your going to seal it with some kind of a clear lacquer..... then under no circumstances use MDF from a builders merchants...... all MDFs are not the same quality and builders quality is plain awful .... look for manufacturers like Medite which is a top notch brand and worth the extra expense.

Also use a high build MDF primer especially for the edges.

You're along the right lines here, but I would hazard a guess that at the moment in the UK over 95% of the MDF available is from one of Caber (Norbord), Medite or Kronospan - all UK manufactured. The issue is, the overwhelming majority of this will be lightweight or 'trade' (as it was rebranded around 10 years ago), this a lower density panel than the traditional standard grade. Approximate 'target' densities are:

Standard 700kg/m3
Trade 550kg/m3

Basically, the lower the density, the less wood in the panel so the more paint is required to get a finish, the lower density panel absorbs can suck up paint like a sponge compared to the denser material.

Most local timber merchants, the big DIY sheds and builders merchants will offer the LW/trade as their only choice without making it obvious, if you find a specialist panel supplier and ask specifically for full density standard grade this should be better for painting. Much the same applies to MR MDF, this used to be denser but recently the majority of this moved over to LW as well.

If you're working in 18mm then the specialist panel suppliers will probably have deep router grade, this is a denser panel and will take paint very nicely.

I don't know a lot about woodworking itself but I am well placed to answer any questions on panels if anybody has any.

Yes your right .... the ‘builders spec’ mdf is much lighter which goes with the whole density argument.

Trade secret reveal.

If you paint and then seal ‘builders spec’ mdf the mdf will split through the exposed ends and looks unsightly. Painted is generally fine but seal it and you will see hairline cracks appear, this doesn’t happen with the better quality/cabinet making grade.

We buy ours from timbmet.

[XCP]

singlecoil said:

and cutting it...

I get my supplier to cut and lip it.

[wolfracesonic]

I think we must have managed to put mr.grooler off going anywhere near MDF

[loughran]

One other thing, MDF isn't an ideal material to use for shelving. 18mm or even 25mm will sag in time if not adequately supported along its length, especially if used for heavy items like books.

If a shelving unit is being constructed, a back can be fitted to brace the structure but even then an 18mm shelf longer than say 500mm and wider than 200mm will bow in time if it's required to support any kind of weight.

Similar scenario with plywood, though not as pronounced. The structure of manmade boards is just not as rigid as the real thing.

[XCP]

I have made floating shelves to solve this problem.

[loughran]

That is cunning.

What do they float on ?

[singlecoil]

loughran said:

One other thing, MDF isn't an ideal material to use for shelving. 18mm or even 25mm will sag in time if not adequately supported along its length, especially if used for heavy items like books.

If a shelving unit is being constructed, a back can be fitted to brace the structure but even then an 18mm shelf longer than say 500mm and wider than 200mm will bow in time if it's required to support any kind of weight.

Similar scenario with plywood, though not as pronounced. The structure of manmade boards is just not as rigid as the real thing.

These are very good points.

[akirk]

loughran said:

One other thing, MDF isn't an ideal material to use for shelving. 18mm or even 25mm will sag in time if not adequately supported along its length, especially if used for heavy items like books.

If a shelving unit is being constructed, a back can be fitted to brace the structure but even then an 18mm shelf longer than say 500mm and wider than 200mm will bow in time if it's required to support any kind of weight.

Similar scenario with plywood, though not as pronounced. The structure of manmade boards is just not as rigid as the real thing.

So, what would you use if you are on a budget, or do you just have to prop the shelves regularly / do shorter runs...
We are moving house soon and plan to turn a 16x12 room into a library with floor to ceiling shelving - we need approaching 300 foot of book space though will probably have to double-bank books to do that... so they need to be strong... and the budget won't be high...

[singlecoil]

akirk said:

So, what would you use if you are on a budget, or do you just have to prop the shelves regularly / do shorter runs...
We are moving house soon and plan to turn a 16x12 room into a library with floor to ceiling shelving - we need approaching 300 foot of book space though will probably have to double-bank books to do that... so they need to be strong... and the budget won't be high...

I'd suggest having plenty of uprights, if you do that you can keep the shelves reasonably thin at 18mm or maybe 25mm. Thing about birch ply is that although as Loughran say it will bend a bit, it won't break. It's like the carbon fibre of timber based sheet materials.

[wolfracesonic]

Just to confuse things even more, look up a product called block board, it resists sagging better than ply, though again, the cut ends need lipping. Good old old fashioned timber is probably best though,as Loughran says, that’s if you don’t want wide widths and don’t want to start gluing pieces together.

[marksx]

I'm planning a bookcase build in our chimney breast alcove. I'm intending 18mm MDF. The shelves would be 400 x 400 based on my plan.

Will that be ok?

[singlecoil]

wolfracesonic said:

Just to confuse things even more, look up a product called block board, it resists sagging better than ply, though again, the cut ends need lipping. Good old old fashioned timber is probably best though,as Loughran says, that’s if you don’t want wide widths and don’t want to start gluing pieces together.

Good shout on the blockboard, use to see a lot of it in the old days, not so much now.

marksx said:

I'm planning a bookcase build in our chimney breast alcove. I'm intending 18mm MDF. The shelves would be 400 x 400 based on my plan.

Will that be ok?

It will depend on how much weight you put on it, I'd suggest constructing it in such a way that you can replace the mdf at a later stage should you need to.

[Mark Benson]

singlecoil said:

marksx said:

I'm planning a bookcase build in our chimney breast alcove. I'm intending 18mm MDF. The shelves would be 400 x 400 based on my plan.

Will that be ok?

It will depend on how much weight you put on it, I'd suggest constructing it in such a way that you can replace the mdf at a later stage should you need to.

One way to make sure is to edge the MDF in hardwood. I've done 500mm MDF bookshelves but with a 30mm facing of oak, biscuit jointed along the front edge which added enough stiffness to prevent sagging.

Also a cheap way of making them look like hardwood shelves at first glance

[Tony Angelino]

wolfracesonic said:

Just to confuse things even more, look up a product called block board, it resists sagging better than ply, though again, the cut ends need lipping. Good old old fashioned timber is probably best though,as Loughran says, that’s if you don’t want wide widths and don’t want to start gluing pieces together.

Blockboard used to be a very good product, widely available made to a good spec in Indonesia and South America. Like with many other products, due to various factors, the UK market now only really has cheap Chinese blockboard commercially available. This is a world away from what used to be available 10 years or so ago and should be avoided at all cost. If you are lucky enough to have a (very) specialized panel supplier near you, you need to be asking for Edi 'Gold Grade' blockboard or something similar but from Spain/Italy but I don't think you will find it.

[Mr.Grooler]

wolfracesonic said:

I think we must have managed to put mr.grooler off going anywhere near MDF

Not quite, but you’re getting there.... I’m waiting for Lavers to confirm they can do a specific delivery day.

I was thinking of using 12mm MDF for most of the uprights and shelves. The uprights will be top to bottom with a series of 3 or 4mm housing joint channels cut into each side of them, and the horizontal shelves will be only 215mm wide which is just enough for most of our shoes and hopefully mean it will all support itself well enough once assembled?

[wolfracesonic]

215mm wide, basically pigeon holes? Mdf will be fine, though I’d use 18mm if you plan on screwing into ‘end grain’, less chance of splitting. Now, do you know what paint your using?

[Mr.Grooler]

Thanks, not planning to need to use any screws. Sheets ordered from Lavers, seems good service. I’ll use one of the basic primers mentioned above!

I’ve also used the excuse of the money we’re saving by DIYing a few things to order a few bits and bobs from Workshop Heaven.... (a mortise gauge and couple of other small items, actually seemed reasonably priced for what they are). Although I’m not sure about a £10.5k plane... !?
https://www.workshopheaven.com/holtey-a1-jointer-p...

[C2Red]

Mark Benson said:

marksx said:

Just general primer or MDF specific?

Just this: https://www.toolstation.com/industrial-spray-prime... - it's acetone based so dries very quickly, meaning it doesn't get chance to soak into the MDF.

I tried this on a flat panel of mdf from Wickes; and it was utterly useless.
Still need to flatten, and it made the grain in an otherwise perfect looking flat panel finish look like rough sawn pine.. disappointing

[Mark Benson]

C2Red said:

Mark Benson said:

marksx said:

Just general primer or MDF specific?

Just this: https://www.toolstation.com/industrial-spray-prime... - it's acetone based so dries very quickly, meaning it doesn't get chance to soak into the MDF.

I tried this on a flat panel of mdf from Wickes; and it was utterly useless.
Still need to flatten, and it made the grain in an otherwise perfect looking flat panel finish look like rough sawn pine.. disappointing

Needs to be light coats of primer, too much and it'll still soak in. Always worked for me but with the MDF the chippies brought with them from their supplier.

[loughran]

wolfracesonic said:

The maple madness continues, following a re-shuffle of furniture, necessitating a taller side table, upon which to rest my cuppa.

I don't need no stinking router..



I'm sure you've also noticed this is the 778 rebate plane with the twin fence guide bars as opposed to the 78 with a single bar set up;)
I wasn't really happy with the resulting rebate it gave, more practice required I think.

We cut mitres the old way round 'ere, badly.



Never mind, the Wolfomatic mitretronic to the rescue!




...a perfect 44.5 degree mitre every time

Mini mortice meet tiny tenon.



A rare bit of creativity from me in attaching, almost invisibly, the lower shelf to the legs. I drilled the
pockets with a flat bottomed forstner bit, screwed in a small gauge trim screw, then filled the pocket
with araldite; quite chuffed with the result.



The finished result, the top infilled with a piece of vegetable tanned, Horween leather to match(ish)
the furniture, the keys(?) on the corners American black walnut cut off the end of my mitre gauge attachment
I think I'll have a piece of glass cut to sit on the top, to try and protect the leather.
Overall happy with it, good from afar but far from good may be a bit to strong but it got me out of
the house over the holidays

Epic adventuring in woodwork Mr Sonic, I take my hat of to you, in a world of electric routers and laser adorned mitre saws it's rare to see such progress with traditional tools (especially in maple). I haven't used a hold down like yours for many years... it was around the same time I last shot a mitre with a plane.
They do say the miter joint is the most difficult of all joints to perfect. Half a degree here... a quarter degree there, all add up a big gap when you multiply by 4.

I've not heard of Horween before so that was an interesting Google.

Your rebate plane got me thinking about fillisters and sash fillisters and ploughs. And then all those moulding planes so beautifully made to do one job and one job only ! I've been toying with the idea of making a nice tool cabinet and filling it with the tools I use and some tools I would like to use so I thought I'd have a look around and see what the state of play is in the world of antique tools.

Seems there's a market in America for nice stuff !



Such a beautiful thing, state of the art from a time before electricity was common. Suitably costly of course, there's a good chance it won't be making an appearance in my new tool cabinet any time soon.

https://www.jimbodetools.com/collections/planes/pr...

Likewise a similar plough from the same site.

https://www.jimbodetools.com/collections/planes/pr...

Tools like this make me think of the men that used them and the work they produced.

Good to see someone is carrying on that tradition Mr Sonic.


Edit to repair link.

Edited by loughran on Sunday 12th January 21:53