Help me pick a good primer for my box

[ma_tt316]

I can't decide what kind of primer to use on my sub enclosure. I've found a few that I like but not sure how well the MDF will take it. Here's what I'm loooking at:

http://www.rustoleum.com/product.asp...ct_id=27&SBL=1

or

http://www.kilz.com/pages/default.aspx?NavID=23

If there are any more kinds of primer that are good lemme know.

[BobEllis]

I've used both with good results. The spray can is a little easier, because it goes on smoother than brushing Kilz - you trade sanding time for expense.

What kind of finish are you after? If you are after a piano gloss and have access to spray equipment, give PianoLac a try. At $80 for a quart of filler, black undercoat, clear topcoat and rubbing oil, it may seem expensive, but I used $100+ worth of rattle cans getting my 1 CF satellites finished. Pianolac builds fast, you only sand every third coat and it buffs to an incredible gloss. While not quite as black as a nitrocellulose lacquer, it is very nice looking. the pore filler took one coat, you can spray 3 coats day.

Just a happy customer. He's got good prices on sandpaper, too.

EDIT: Pianolac is water based - easy cleanup.

[ma_tt316]

Here's the fish I want to use. http://kilz.com/pages/default.aspx?NavID=44 I really like the Dark Blue.

[ma_tt316]

Can anyone suggest a good quality primer that is know to hold its own when appling to MDF. I tried some on a piece of scrap MDF and it soaked right though. Also would spray primer hold better then brush on (less soakage)? Thanks.

[ma_tt316]

Forgot to ask should I fill the seems first before appling primer or after?

[BobEllis]

Just about anything you put on the edges will soak in quickly. One important step that took me a while to understand was spend as much time with each finer grit as the one before it. If you spend 10 minutes scratching it up with 100 grit, spend ten getting those scratches out with 150 and so on. You want to minimize the depth of scratches that you need to fill. Somewhere around 150 grit to 220 is where you should stop before priming MDF.

I fill the seams before priming. I use lightly catalyzed body filler, so it stays runny long enough to get into the cracks. over fill slightly, since it shrinks. I've found that nothing will get into a tight seam, but that automotive paint still sags into it. spray several coats on the seam to fill before sanding smooth.

Spray cans have more solvent than brush on types, so you get less paint solids on the surface, but it is smoother and you may find yourself less likely to sand through. You are using a sanding block, aren't you?

Although it may seem like an ad, I am really just a happy Pianolac customer. The fastest prime/fill on MDF that I have ever used is the pianolac creme pore filler. It is more liquid than the name suggests, but it sealed up in a single application - even on the roundovers. I did not notice any soaking in when I applied the first coat of black. It is a waterbased product, so it may not be suitable for application under all finishes.

A correction to my earlier comment about Pianolac. My first attempt at rubbing out my cabs left some scratches. Yesterday I resanded with 600, 1000 and 1500 grit, and buffed them out. The gloss improved to the point that they are mirrors and more importantly, they seem blacker. Now the black is on par with the lacquer on my earlier cabs.

So, if you are after a really black satin finish, I'd say look eleswhere, but for a black high gloss finish, pianolac is tough to beat. It gets even tougher when you factor in how much more quickly it goes on and rubs out. They advertise lower cost of materials than similarly priced automotive type paints, because it has higher solids content. I haven't sprayed anything but Pianolac. But, I did spend 25% less on materials than lacquer spray cans on a similar project and have enough left over to do at least one more pair of cabinets. Of course if you consider the cost of the spray rig, that math goes out the window. But, I use my compressor for all sorts of other things, too.