Painting louvered doors

[dlminehart]

A friend has asked me to help repaint 4 large louvered doors that separate her dining room from the living room and the kitchen. I believe they currently have a latex paint on them, to be covered with same in a different color.

How would you recommend going about the prep work? I'd thought I could use a nylon scrub brush with Jasco TSP substitute, hose down outdoors to rinse, and then let dry for an hour or so before priming.

I thought I'd use an alkyd primer, perhaps one paired with the topcoat and tinted toward the topcoat color.

I figured that spraying could go faster and better than brushing. I have the HF HVLP sprayer, as well as the Wagner Paint Crew. The HVLP is best for thinned liquids, and I suspect it might take a few thinned coats of both primer and topcoat to handle the latex. I've not used the Paint Crew, but it seems suited mainly for big exterior jobs. I'm wondering about using this HF product: http://www.harborfreight.com/cpi/cta...emnumber=47274 . It's similar to the typical Wagner gun with 1 qt plastic jar, but available for less than $20. Anyone familiar with its use?

I want to do both sides of the doors in the same session. Seems like this either involves attaching hooks or something to their tops so they can sprayed on both sides while suspended vertically from a rope, or putting nails in both top and bottom so they can be sprayed while resting horizontally on the nails suspended on sawhorses, first on one side and then, after rotating the door, on the other. Anyone used either of these methods and care to report their results?

[pecker]

I personally would not put an alkyd primer over a latex topcoat. But here is what http://www.truevaluepaint.com/conten...px?con_id=1419 says:

"For interiors:
You can safely apply latex over oil, or oil over latex, but only if the previous finish is flat or if it has been sanded. If in doubt about what's there, you may want to cover first with a primer of the same composition (alkyd or latex) as the paint you choose to use.


For exteriors:
Oil should not be applied over latex. The best exterior combination is latex paint over alkyd primer. "

[cabinetman]

I haven't tried an electric sprayer with latex. I would think you would have to thin it quite a bit. If you go to a large nozzle, the finish may not come out so smooth. The problem I get with spraying louvered doors is runs due to all the angles and the slats being so close together it was difficult to get good coverage of the slats without hitting all the corners and edges.

At the time, I used lacquer, and did light coats. Now, I'm trying not to use lacquer and I would use an alternative, like waterbased polyurethane.

I've suspended them both ways (vertically and horizontally) and it sure beats waiting for one side to dry. Doing them horizontally makes it difficult to turn over with one wet side, plus, you get blow through which puts material on the second side. Doing them vertically may be difficult to reach depending on how long they are. It's a matter of being able to see where you're spraying. I suggest whichever way you choose, to get a lot of light on the doors so you can watch the "glare" of how wet you're getting them.
.

[JimD]

I agree completely with cabinetman about the light. Louvers are especially hard to see how much you are getting on.

I have had bad luck with inexpensive paint sprayers that basically pressurize the paint and shoot it out. I did not try the HF, however. The Wagner seems pretty reasonable to me.

There is an article on the tips part of the Highland Hardware website about thinning latex paint with Resisthane for spraying. In addition to thinning the paint it makes it more durable. Resisthane is a water based lacquer.

Jim

[dlminehart]

I wish the Resisthane were available locally. Have to do the job this weekend, and don't have time for shipping it from Pennsylvania. Maybe I can have my friend postpone the project for a week.

[cabinetman]

Resisthane is a water based lacquer.

Jim

A few facts about Resisthane here.
.

[JimD]

Hood Finishing has a lot of facts about Resisthane at their website. I order from them sometimes but the website does not work for me, I call them. I got the last gallon from Highland Hardware in Atlanta.

While I agree that water based products are not chemically the same as solvent finishes, I do not object to desribing them this way because it helps those of us who have been around long enough to work with the solvent finishes. I get the feeling that there may come a day when we will be an exception. The characteristics of Resisthane that are like a hard pre-cat lacquer are it's fast drying time (1 hour or less), the fact that it adheres to previous coats by disolving them a little and the fact that it is hard and durable. Polys and varnishes do not dissolve prior coats, they adhere by depending on a little bit of a rough surface. Shellac also cuts into the prior coat but shellac is not known for durability so I don't think vater based finish suppliers want to describe their finish as like a shellac. Shellac is usually not clear and water based finishes typically are - like lacquer. Resisthane drys so fact and sands relatively easily so it also works well as its own sealer. I do not study the chemical formulation of finishes, just their characteristics (although I always enjoy cabinetmans postings).

Jim