Gloss Finish on MDF

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Jaguar999

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Hi Guys

So this has nothing do with anything audio related but thought that I'd share my build of an aquarium/coffee bar and how I achieved a gloss finish on panels using OTC rattle cans. The reason for this thread is to assist anyone looking to attain a mirror finish on MDF but does not have access to a compressor. I have also listed where I sourced some of the tools/materials as I?ve always found this information to be really useful. BW may be convenient but is often expensive and doesn't have a wide range of products. 

Before I continue it?s worth mentioning two things that have been covered before. Firstly do not  skip the preparation steps and secondly, if you are going too attempt this please exercise patience. This was my first attempt at this so I'm sure more experienced members would shed light on how certain things could be done more efficiently. All I've done in this thread is note what I did and what seemed to work for me, along with any mishaps along the way.

My cabinet was constructed entirely of 16mm MDF. I found BW to be the cheapest on MDF, think it?s around R400 for a big sheet (2750 x 1830) that they will cut to your specified dimensions. All spray painting was done using Rust Oleum Painters Touch rattle cans from BW. They were running a special in December and cost R80 per can.

Paint


I used the gloss black and gloss red from the same range as a base coat. Please be cognisant of which clear you purchase from the range and ensure that it is the "Gloss Clear".

Once the cabinet and panels were constructed, I used Ian?s (JimGores) guide for preparing the wood.

Step One: Filling
Here I used a combination of wood filler and a dry wall filler to fill any nail holes and mitre joints. I didn't bother applying this with a scrapper but rather just applied it with my finger ensuring that the filler penetrated any gaps. I also applied the dry wall filler along the edges to prevent any porous effects coming through on the finish. I let this dry overnight and sanded the filled areas with 100 GRT sandpaper followed by sandpapering the entire panel with 320GRT. All sanding was done by hand. The one thing I HIGHLY recommend is investing in a sanding block, it?s under 50 bucks and makes sanding a whole lot easier. I repeated this process thrice until I was happy that everything was perfectly smooth. The one thing I found is that when sanding with 320GRT dust fills any tiny crevices. What I did, was run a very slightly damp cloth over the wood after sanding to expose these imperfections and focus the sandpaper on these areas to get the area smooth.
Items I used




Step Two: Sealing
I separated the filling and sealing into two steps purely because I wanted to ensure that there were no gaps or cracks at the mitre joints. However, this may be an overkill and can be bundled into one step. For sealing I mixed a 50/50 ratio with water and wood glue and applied it generously with a brush all over the panels. I then let the panel sit overnight and sanded with 320GRT the following day. Once I was done sanding, I brushed off excess dust and wiped the panel with a damp cloth and let dry for a few hours in a warm area.
Sanded and Sealed




Step Three: Priming
After the panels were dry I started the priming process. I shot one light coat, let it dry for 5 minutes and then shot a further 3 coats at 5 minute intervals and left to dry for two days.  Once dry I sanded the panel with 600 GRT sandpaper until the primer was perfectly smooth. I cut through the primer at the edges during the first sanding pass so I suggest you  try not to apply to much pressure when sanding edges and avoid sanding the same area for a long period. Once I was done sanding, I brushed off excess dust and wiped the panel with a damp cloth and let dry for a few hours in a warm area. I repeated the priming process twice so as to have a decent layer of primer.
Primed panel




Step Four: Base Coat
I opted for gloss black and apple red for my design. Here I shot a very light coat to begin with followed by 5 light coats at 10 minute intervals - this constituted my ?first base coat?. PLEASE avoid the urge to go heavy, I made this mistake and the layers ended up bubbling and I had to start all over. You want to go over an area with one pass, your second pass should only overlap the last pass by 50% and not more. Do not go over the same area twice!

I live in a complex so my DIY is done outside on a patio, if you are in a similar situation I suggest spraying in the mornings as there?s less bugs around. Also be armed with a fly swatter to chase any bugs flying about the panel whilst it?s drying. You may look like a Muppet to your neighbours but it would mean an insect and imperfection free finish.

The paint can states you can let the paint dry for 24hrs before reapplication ? this is utter BS. On the first attempt I left the panel to dry for  48hrs and the paint crinkled the second I started the process of the second base coat and I had to start all over. On the second attempt I left the panel to dry for four days before wetsanding with 800 GRT sandpaper. This was my first time wetsanding and I picked up a few things. You do not need a lot of pressure, ensure the surface is adequately lubricated (dishwasher liquid mixed with water from a spray bottle worked fine) and always visually inspect the area as you sand. If you cut through to the primer ? STOP sanding. The last thing you want is to cut through to the wood. After sanding you should end up with a surface that looks pretty flat/matt, this may look pretty crap but you?ll get the gloss back during the polishing process. For routed edges I used sandpaper on a foam applicator to get into the grooves. I then wiped the panel with a damp cloth and let dry before repeating the same process for the ?second base coat?.

Red panel after first base coat


Black panel after first base coat


Black panel after second base coat


Step Five: Clear Coat and Polish
This was necessary to achieve ?depth? in the final finish. I let the second base coat dry for four days before wetsanding with 800GRT sandpaper and then started the application of clear. Again disaster struck, the first application of clear resulted in the base coat cracking really badly - I could even see through to the primer. This would have been the fourth time I would have had to restart the entire process so I was losing patience  :fuse: Before I ruined another panel I decided to just abandon the clear on one of the panels and start the polishing process. This would get rid of the ?orange peel? effect and ensure a smooth finish. I wetsanded the second layer of base coat with 1500GRT, 2000GRT and finally 2500GRT. During this process be very gentle with the sanding, if the paper puts up resistance spray some more lubricant over the surface. As you move up in grit you?ll notice that the gloss comes through stronger and stronger. After finishing sanding with 2500GRT I started polishing the panel. For this process I used Menzerna PF2500 and Meguiars Scratch X using a polisher applicator pad. To finish the process I used Menzerna SF4000. The entire polishing process was done by hand, here you?ll need a lot of elbow grease to bring out that mirror finish.

Disaster


Red panel after polishing without clear




I then restarted the process on the damaged panel but was determined to get the depth I was after. This time I used some test pieces throughout the process. This allowed me to play around with techniques to get things right. Eventually I got the best result by applying the clear in three light coats 15 minutes after applying the final light coat of the second base coat. I then shot 3 light coats of clear at 10 min intervals and left this to dry for almost a month. This ensured that clear cured entirely. Ian suggested smelling the surface to gauge if the paint had dried completely which worked like a charm. The paint smell only subsided after the third week so for good measure I left it to cure for a further week. After the clear cured I resumed the polish process as above.

Mirror Finish


Final Finish  :Whoohoo:


You?ll notice the distinct ?depth? effect that is achieved when using the clear on the black panel over the red panel where I did not apply clear.

And the final product with all panels assembled.










I still need to put some additional touches on the glass before adding my Nespresso machine but for the better part I'm done with the cabinetry

Sources of material/tools:
MDF, 100GRT sandpaper, filler ? BW
320GRT sandpaper, sanding block ? Gelmar Fourways
600GRT and higher sandpaper ? Maroun's Midrand
Menzerna polishes - http://www.crazydetailer.co.za/

For my next project I will definitely invest in a compressor as I would like to see the results using 2k paint  :clap:

Anyway I?ve tried to be as elaborate as possible and hopefully this may be useful to someone looking to achieve a gloss finish with rattle cans  :dop:

Cheers
Meilan 
 

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