MDF finishing help please

[steve_g]

I don't make cabinets... There are those who enjoy the trade and can make a living at it. I don't. My #1 objection to building cabinets is that no matter how fine a job I do designing and constructing them, the end result is judged by the last 3 mil of finish applied to them.

That said... a friend of mine saw some of my V carved panels and some of my Sculpt Nouveau finished projects. She decided that she wanted her kitchen cabinet doors re-done in SN finished MDF V-carved panels... That sounded challenging and fun! I made several trial patterns, painted them In a latex paint color matched to approximate copper oxide and hung them on her cabinets. Here's where I ran into trouble... She loves the result... the painted result. Now that is the way she wants them finished, not the Sculpt Nouveau.

I'm unhappy with the Painted result because of the swelling or "grain raising" that the latex paint does to the MDF in the carved areas. I thought I would ask those who work with machined MDF doors all the time how they finish them before I experiment with shellac, kills, etc.

Thanks!

Steve

[kubotaman]

Steve I have done lots of painting of MDF. I use Zinnzer oil base primer and it will give you amazing results. I spray three heavy coats on the MDF. I sand between the second and third coat. Sand with 180 and on last coat I sand with 220 Freecut sandpaper. You can then give a finish coat of water base or oil. It doesn't matter. Remember to make sure it dries overnite and it will sand like chalk. If it sands a little hard then let it dry longer. You will get beautiful results if you take your time!

[myxpykalix]

There are better experts at this then me but let me tell you my experiences.

The first time i cut mdf to make my waincoting I asked no advice and just started spraying the mdf. What happened was the sections that still had the paper on, the paint just ran down and the sections that were cut just soaked the paint like a sponge.

The next time i needed to paint mdf i got advice from Joe Crumley (I think) and before and after i cut the mdf i took a 50/50 mix of titebond glue and water and painted the mdf very liberally with it and let it dry.

After i cut it didn't "raise the grain" like it did in my previous experience. It still needed some sanding but not like before and allowed for your final finish to go on more uniformly and evenly. The surface was far more solid and the "pores" of the mdf were closed because you had a harder surface to cover.

Others may be able to explain it with more detail but that is what worked for me.:D

[kevin]

Steve the doors look good

Oil vs water base sealer .You nee a sealer I use to use to use 5 in 1

By a customer I used Benjamin Moore interior primer .It worked amazing
Your door is hard to seal with all the detail It just drinks it up

Remeber the most important part is sanding in betwween coats

There also water and wood glue .It can create a surface on a surface and crake

I always try to keep it simple on a kitchen due to all the parts with things going wrong

KISS

Good luck

[Brady Watson]

I use to use to use 5 in 1

Wow! You REALLY got your money's worth! :D

-B

[cabnet636]

i use HDF for this,, you can purchase it melamine finished on one side only or hdf all sides, world of difference and it is the money time difference

those are some doggone good looking doors!!

[steve_g]

James:

You sent me searching my Dallas area suppliers and coming up empty. Where do you get high density fibrewood?

I'm being told it's available in full truckloads only! :eek:

Steve

[cabnet636]

yep economy has most board manufactuers not wanting to store slow movers,,

look for a companu who makes mdf doors, find them find the supplier,, here in sc i get it from meyer in west columbia 803 926 7115.. he stoks .75 and 1 inch for me,, i use it for sculptured panels

www.panelusion.com (http://www.panelusion.com)

[tgm]

We use an ML Campbell product called 'Claw Lock' made specifically for priming MDF products. It's a two part catalyzed product that is tintable and when used according to the instructions will create a perfect base for a glass smooth top coat. Dries in less than 1 hr ready to scuff and re-coat.
Not the cheapest date on the block but the results are awesome. If anyone has purchased Conestoga's primed or finished MDF door products this is the finish that they use. We use this finish on commercial casework when a painted finish is specified and we have always had awesome results. Sprays and hardens like an automotive finish.

Good Luck,

Tom in PA

[jkaras2000]

Hi Guys: Great job on the doors Steve. Tom, can you tell me if you can brush the Clawlock on MDF doors, or does it need to be sprayed. Also, do you have to mix it with a catalist, or is it premixed? Thanks Joe :cool:

[tgm]

Joe,

Best results are achieved by spraying it on. It has to be catalyzed at time of use and it is very easy to use. It can be thinned up to 10% depending on your equipment.

Good Luck,

Tom in PA

[loriny]

With my HVLp I've thinned the clawlock up to 30%. It works but builds slow. Getting it sprayed with a good airless @ 100% does a beautiful job. Most of m MDF is done with Target pigmented water based lacquer. Sand before, lay a coulpe thin coats on, then let dry and lightly sand with 320 or 400 grit. Then one or 2 heavy coats. Pretty good results but not like the Campbell solvents.
Lorin

[cabnet636]

we spray a lot of mdf doors,, always spray two coats on machined areas before first sand (first coat is absorbed second starts build) one coat on non machined areas,, clawlock is firstclass we switched to nanochem (commercial only) as we are system specific on all our finishes. used mlc for many years before that.

[steve_g]

Thanks to all who contributed to this thread so far! I was unable to locate any HDF in the Dallas area even after contacting the largest distributors in the metroplex. I look forward to trying this product in the future! The MLC Claw lock also does not appear to be available in my part of the state... I found suppliers in Houston who had it listed on their web site as available, but likely it can't be shipped UPS or USPS...But I didn't try. I did pick up a gallon of Zinsser oil base primer at HD ($16.00) and will try it early this week. I'll let you all know my thoughts.

Steve

[steve_g]

I burned up my year old compressor spraying the Zinsser... apparently "Huskey" isn't. I decided it was time to buy a real "man's" air compressor. Trying to save a buck I searched Craig's list and found an ideal candidate. A trip across Dallas to a rural suburb resulted getting a chunk bit out of my leg by a Pit Bull dog. The owner of the compressor called the dog off by name and then denied that the dog was his...



After a day of doctoring and police reports, I'm convinced that paying full price for a new compressor would have been cheaper.

I still don't have a compressor.

Steve

[myxpykalix]

"After a day of doctoring and police reports, I'm convinced that paying full price for a new compressor would have been cheaper."

Possibly, but not nearly as exciting.....:eek:

Maybe with the money you will get from a lawsuit it will pay for a new compressor:D
Although i'm usually reminded in cases like this that this old saying applies: "You can't get blood out of a stone":rolleyes:

Hope it works out for you and you're ok!:)

[steve_g]

A follow-up here... My (adult) children got together and bought me a "real" compressor for Christmas. Apparently their projects were suffering too!

Campbell Hausfeld 5 HP, 16 CFM should run a spray gun without taxing it too much!

Steve

[wayne_walker]

Steve,

Congrats on your new compressor!!!


"5 HP, 16 CFM"
The key is 16 CFM @ ??? what pressure?

In general, yes, that pump should handle a paint gun. Several things come into play when determining if you pump will handle your requirements.

They are...

The material you are using and the recommended air pressure to properly apply it. This is using the manufactures recommended reduction.

Determine what type of gun you are using. Gravity feed, gravity feed HVLP, siphon feed, pressure feed, pressure feed HVLP or etc. Some types of guns use a lot more air than others.

The fluid needle, fluid nozzle, and air cap combination on the gun you are using. They are machined to work together? If the air cap does not match up with the air cap then it does not properly atomize the material, producing a poor finish.

So back to the pump, if the 16 CFM is @ 30 PSI and your material recommends 60 PSI then your pump is only delivering 8 or 9 CFM @ 60 PSI. It will handle your air demands to a point. The longer you spray the less air you will have available. Your recovery time of the pump will start getting longer and longer. The pump will start getting putting out much hotter air!

Now lets talk about the size of the tank. With a small tank, the air will not have time to remain in the tank to cool off and drop the moisture out of it. Make it a habit to drain your tank on a regular bases.

From the tank to the gun, you should think about the air cooling off and the moisture condensing to water. You want to mount a water trap/filter as far from the source as you can. This way the trap has a better chance to trapping the water and dirt. Here is a link that will help you lay out an air line system.

http://www.sharpe1.com/sharpe/sharpe.nsf/Page/Air+Piping+Layout

I sold to body shops quite some time ago. I don't think this info has changed much over the years.

I hope this helps you get started down the road. Water/Moisture in your finish is a real pain.

Wayne

[steve_g]

Wayne
Thanks for taking the time to clarify what the specifications on a compressor mean. It's too late for me, but anyone coming across this thread in the future will be well advised! I was a little irritated that my new compressor is so large ...An 80 gallon tank seemed unnecessary with 16 CFM @ 90 psi. Now that I know about the need to cool off the air to drop its moisture, I'm pleased.

Thanks for the link... I hadn't given any thought to moisture issues. I think I'll get an automatic drain as the spot chosen for the new compressor isn't convenient to get to.

Thanks again!

Steve

[wayne_walker]

Steve,

You should have plenty of air and the tank size is good.

You can put in an elbow and run a pipe to a good location then put a petcock to drain it. The air will force the water uphill to a certain degree. Copper or brass would be best since there will be moisture in it All of the time. I have a galvanized extension on mine and it has not been a problem but over time it will rust thru.

I also HIGHLY recommend that you have a shutoff at the tank for the air line and use it every night. I also cut the power to my pump. It is not a good feeling to open the door in the morning and have the pump running with a blown air hose leaking like you have a blow gun wide open.

Just a thought...

Wayne