built in wardrobes

[chief]

hi,

i am making some built in wardrobes out of veneered mdf, the wardrobes are the length of the wall. I plan to make three separate wardrobes a then screw the wardrobes together, as you would do with say three kitchen units that sit next to each other.

The wardrobe will be made up of two sides, top and bottom (all 18mm veneered mdf), and a back (4mm mdf), all of which will be screwed together. Then i plan to screw battens to the two sides to support shelves.

I am not a chippy by trade and i have a few questions if you don't mind answering them.

1. To join the two sides, top, and bottom, is it just a case of screwing the mdf together butt joint style?

2. I have been advised to use 3.5 x 45mm screws to screw together the wardrobes, but i am finding it hard to get any so would it be ok to use say 4 x 45mm instead? or what other screws would you suggest?

3. What size battens should i use to support the shelves?

4. What size screws should i use to screw the shelves support battens to the sides?

5. As i am using veneered mdf oviously i don't want to paint the mdf, so it it a case of just sealing the exposed mdf edges? And what should i use to seal the mdf edges?

6. What would you advise for finishing off the exposed mdf edges, veneer or a hardwood trim? i am inclined to use a hardwood trim but you trade boys will know which is better to go for.

Sorry for so many questions but the materials are expensive i don't want to make a very costly mistake. :roll:

All advice welcome

 

[MooreToolsPlease]

Hi Chief,
I have done a fair number of built ins similar to yours.
For the joints of the sides to the top and bottom, I usually butt joint and screw them.
The screws I use are called 'Confirmat' Screws,
Here is a pic :

They grip a lot better than 3.5 x 45 or 4 x 45. They do require a pilot hole drilled with the associated drill bit.
Remember to place the screws about 3 inches from the ends of the side, or the edge will blow out.
The battens for the shelves can be anything really, I would be inclined to use 2 inch rips from the off cuts of your veneered mdf. Fix with 4 x 30 screws.
I usually lacquer my built ins, this consists of 2 base coats and then 2 top coats. Without a spray facility I would probably use a brush on sanding sealer, then perhaps a varnish but I'm sure someone else will better advise you on this.
The edges I usually use iron on edging. It's quick and easy.
If the cabinets are for a high end job I will use a solid lipping.
Hope this helps you out

 

[jasonB]

1. I use biscuits to help align the joints as well as screws

2. Carcase screws would hold better, I use these 4mm clearance hole & 3mm pilot so the MDF won't split

3. 20x30mm finish size would do but I use metal shelf studs

4. Use a screw that will have about 15mm of thread into the MDF, so 35mm if you go with 20mm batten.

5. waterbased varnish/laquer to finish the face of the boards

6. Wardrobes don't get too many knocks so iron on real wood veneer edging is fine.

JAson

 

[johnnyb]

i pretty much agreewith theabove but i would use a face frame to hide the mdf edges even with lay on doors. apply water based lacquer with a large paint pad. a level base is vital......

 

[chief]

thanks for the advice guys , but i have a few more questions if you dont mind.

1. What glue do you use for the biscuit joints?

2. Do you also glue along the rest of the butt joint?

3. Is veneered mdf safe to use in a childs bedroom? (really paranoid about this)

4. Sorry for my ignorance jasonb but i am not sure what you mean by clearnce 4mm clearance (i do understand what you mean by 3mm pilot hole though )

5. Sorry for my ingnorance once again ,johnnyb when you say use a face frame to hide the mdf edges, to you mean using a hardwood trim instead of veneer on the front edges?

thanks

 

[Steve Maskery]

a level base is vital......

Actually, that should read:

A LEVEL BASE IS VITAL!!!!!!!!!!!!

Cheers
Steve
(DAMHIKT)

 

[MooreToolsPlease]

Clearance hole goes through the cabinet side, so that the threads from the screw only thread into the top/bottom panel

 

[chief]

Sorry i forgot to ask, is it ok to use biscuits on veneered mdf?

 

[Steve Maskery]

Actually can I suggest an alternative method of screwing them together?

Make all the panels out of 17 or 19mm veneered MDF.

Use pocket hole screws to hold it all together. The pockets can all be cut on faces which are not seen. This is done by having the back overlapping the top and bottom, and the sides overlapping the top, bottom and back. The pockets are then cut into the side edges and back edge of the top and bottom panels, and the sides of the back panels. It's all invisible when assembled.

Alignment can be done with biscuits, but loose tenons, either routed or Festool Dominoed are better, there is less play, But then I would say that wouldn't I? Personally I wouldn't glue then up. I don't see that it adds an enormous amount of strength and you may want to dismantle it all one day. Screws alone make a very strong carcases, and loose tenons just pushed into a well-fitting mortice add as much alignment as you could wish for.

I've done two large structures this way and will probably do a third before Christmas. It's quick easy, cheap, neat and above all excellent.

Pocket hole screws are available from Axminster and there are several jigs on the market, the best-known being Kreg.

I cut mine with a router jig, but then I would say that, too, wouldn't I?

HTH
Steve

 

[chief]

Is there a rule of thumb for what size pocket hole screws to use?

 

[chief]

please excuse my ignorance steve maskery, but after reading your last post again i am a little confused.

With regards to using the original method for screwing the wardrobes togther. i was under the impression that i should butt joint the top and bottom panels to the side panels with the side panels overlapping the top and bottom panels, screwed through the side panels (clearance holes mentioned earlier) into the top and bottom panels (piolt holes mentoned earlier). Then the back panel overlapping the side panels, top panel, and bottom panel, screwed through the back into the sides top and baottom panels. If i have understood this method correctly, then wont all the screws not be visible. Again sorry for my ignorance but i am not a chippie.

 

[jasonB]

Re hole sizes, 4mm counter sunk hole in the carcase sides and 3mm into the edge of the top/bottom/fixed shelf. Carcase joints as you describe above.

I leave my biscuits dry.

Both the carcase screws and pocket screws are drilled from the outside of the carcase so don't get seen unless you have an exposed end panel in the case of carcase screws, the pockets will be through the top/bottom so will only be seen if you get on a ladder :wink:

The majority of MDF sold today is low formaldihide so there is little risk of it gassing off.

A face frame is generally wider than the thickness of the carcase and gives a more traditional look like this and is mostly used with inset doors but can also have layon doors, in both cases you will need specific hinges.

BTW what type and construction of door are you going for :?:

Jason

 

[Steve Maskery]

Does this help?




All the pockets are on hidden faces, so nothing is visible inside nor even on the wardrobe sides.

Cheers
Steve

 

[chief]

Cheers guys you have been a great help.

As there will be no end panel i think i am going to use carsace screws, but i do link the pocket screw method and i think i will use it when i redo the wardrobes in my own room.

Regarding the doors, i plan to use stanley sliding doors. I thought i would make the furthest end panels (on either sidewall) 80mm wide than the other end panels, so that the doors sit in front of the wardrobes but flush with the two furthest end panels (on either wall).
Is this a good idea :?:

I know you trade guys say mdf is safe, but my daughter is autistic and i dont want to put her at any other health risks so i thik i will use a different veneered sheet mterial apart from mdf.
Are all 18mm sheet materials strong enough to make wardrobes with :?:
Will veneered melamine boads be ok :?: