MDF finishing?

FL630

FL630

FL630

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Hello OCUK folk,

I've decided to make my own stand for my 22L nano aquarium, rather than spend £80 on a horrible factory made one.

I've decided to use 18mm MDF because a) I know nothing about making stuff like this, b) it was cheap and c) I started this project on a whim whilst passing by B&Q earlier.

Structure wise, I'm confident my design will hold the ~40kg tank as it will be supported vertically by central pieces of board, that is until it gets wet...

So, being a total idiot on the DIY front, how does one go about finishing an MDF product to make sure the odd drop of water doesn't turn my stand into a swelling mess?

I'd ideally like it finished in gloss white. From what I have read the biggest issues are the edges needing to be sealed, and anywhere I can expect to have a screw drilled through the MDF.

Thank you in advance!
 
If its made from MDF from B&Q its going to require a lot of prep

Typically MDF from big chain stores is lower grade and when cut will leave a "fluffy" edge which no matter how much you sand will remain "fluffy"

If ever you are going to build something from MDF that is going to be painted always use moisture resistant "M.R." MDF from a reputable timber merchant. It may cost slightly more but is worth it for the easier finishing. The harder green center sands to a nice finish that paints very well, it also accepts screws better with less chance of rip out.

As for your project I would make the unit and sand only the seen edges with a D.A sander, starting with 120 grit then going straight up to 240 grit. You will likely need to then primer the edges, leave to dry then sand with 240 grit again. Rinse and repeat until the "fluffy" edge is nice and smooth then you can start to top coat.

DO NOT sand the face sides at all before priming. Once you've given them a light coat then you can give them a light sanding before apply a 2nd, 3rd, 4th coat etc.
 
If you want the best finish scrape a fine surface filler down the cut edges after the first coat of primer. If you are after a good high gloss finish expect to put in A LOT of effort!
 
Okay thanks chaps, any recommended products that I can pick up from my local B&Q/Wickes? I really am that clueless!
 
FL630 said:
Okay thanks chaps, any recommended products that I can pick up from my local B&Q/Wickes? I really am that clueless!
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If it was me I'd buy a stand, unless your really into this or don't mind a slightly rubbish end result you might want to consider descetion the better part of valour!
 
I use MDF for a lot of my projects. Samples:









You can have a good look through my thread here which has some info on finishing.

https://www.avforums.com/threads/thereis0nly0nes-diy-project-builds-thread.1958872/

There's also a build log, here, which has lots of pictures on MDF finishing:

http://www.isrtv.com/forums/topic/12145-r-pod-mkii-vr-enabled/

There is more than one way to skin the proverbial but I find this is a consistent way to get decent results.

NB Blackboard vinyl is a great way to cheat and obtain a great finish on flat surfaces (ok, it's not white ...)





Also consider t-molding for edges. P38 car boy filler is what I use for the rough edges - works a treat but expect to expend some effort to get a good finish

Hope that helps.
 
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From experience, getting anything approaching a high gloss finish on anything more than a tiny piece of MDF is seriously hard work. I'd really consider vinyl wrapping if the shape isn't to complex.
 
Thanks for all the advice chaps. I ended up looking online (before the majority of replies arrived here) and some guy used an equivalent of pollyfiller and sanding to get the edges smooth before priming. I didn't realise that "MDF Primer" as mentioned above was literally all it was called, I assumed it'd be something branded. Anyway a trip to B&Q got me everything I needed. I ended up using 3 coats of primer and 2 coats of gloss. I gave up on the idea of a high gloss after seeing how much effort it would take and accepted standard gloss would have to do.

Overall, it's not going to win any modern design competitions or nods of approval from our Swedish furniture friends, but it's dead strong, fits in with the general theme of my room and it's the first thing I've ever built which is both straight and level. So all in all I'm really happy! Here it is! (Excuse the poor photo)

tank.jpg


The problem is it's got me wanting to build more stuff, I'm thinking desk PC now....
 
FL630 said:
Thanks for all the advice chaps. I ended up looking online (before the majority of replies arrived here) and some guy used an equivalent of pollyfiller and sanding to get the edges smooth before priming. I didn't realise that "MDF Primer" as mentioned above was literally all it was called, I assumed it'd be something branded. Anyway a trip to B&Q got me everything I needed. I ended up using 3 coats of primer and 2 coats of gloss. I gave up on the idea of a high gloss after seeing how much effort it would take and accepted standard gloss would have to do.

Overall, it's not going to win any modern design competitions or nods of approval from our Swedish furniture friends, but it's dead strong, fits in with the general theme of my room and it's the first thing I've ever built which is both straight and level. So all in all I'm really happy! Here it is! (Excuse the poor photo)

The problem is it's got me wanting to build more stuff, I'm thinking desk PC now....
Click to expand...

Nice going and it turned out well. Glad to hear you've got the building bug ... now get cracking ;)
 
valve90210 said:
How durable is that as a finish?

I'm wondering if it would be suitable for use on an arcade cabinet that would be used by children?
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It's pretty durable. I covered my desk with it and it's been good for more than 4 years.



I also have it on my arcade cabinet control panel (and other areas of the cab), albeit with cast acrylic for the main section.

 
valve90210 said:
That does look good!! Methinks I may investigate this then. where do you normally get it from and how easy is it to work with?
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I usually get it from here:

http://www.mdpsupplies.co.uk/blackboard.asp

It's quite easy to work with. Sometimes an extra pair of hands helps when applying it to large surfaces. The surface must obviously be free of any debris otherwise it's like the princess and the pea if you know what I mean. If working around 2 planes and the angle is greater than about 60 degrees, it's best to round off the edge very slightly to avoid bubbling. It can save a massive amount of time on project builds and has a great texture to it.
 
Cheers for the info. Looks like it could be just what I've been looking for.

I will probably wrap each panel individually then assemble the cabinet

Do you think (or indeed have you experience of) vinyl decals being used over the top of the blackboard vinyl will work?
 
valve90210 said:
Cheers for the info. Looks like it could be just what I've been looking for.

I will probably wrap each panel individually then assemble the cabinet

Do you think (or indeed have you experience of) vinyl decals being used over the top of the blackboard vinyl will work?
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No problem. Re the vinyl decals, it could possibly work although the texture on the blackboard vinyl is something to be aware of. Thicker vinyl decals which aren't too small should be ok.

I do have metal stickers applied to another project build (PC display stand) which seem ok:

 
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