Should I use Latex or oil based primer?

[CB]

I have a desk built out of finished plywood that's ready to be primed. I don't know whether to use oil or latex primer. Of course latex is less messy and smelly but I want the finish to be durable. I'll go over the primer with Benjamin Moore's waterborne satin impervo and some polyurethane. I have heard that latex doesn't bond as well and raises the wood grain, but I don't know how true that is. What would you recommend?

[Ken Darga]

CB,

#1---apply a sanding sealing, to the bare wood.

This will seal the wood and raise the hair-like wood fibers---

Sand with 320 grit, remove/wipe up sanding dust, before applying the finish.

  Water-base premium grade finish, will do nicely---

less odor---easier to clean-up.

When brushing, use a quality synthetic long tapered bristle brush---

This will provide a smoother leveling of the painted finish.

Make long sweeping brush strokes---

Will result in nearly invisible brush marks.

  A satin poly top coat can be applied over the painted top panel/desk top working surface.

The poly top coat, will provide a protective clear coating, which will reduce any visible marks,

That may occur during use.   

Apply 3 coats of the poly finished---

Sanding with 320 grit between coats.  

Remove/wipe off all sanding dust, between coats.

Wipe-up the sanding dust, using a clean white lint-free cloth, dampened with mineral spirits.

[James P. Cottingham]

This of Latex as a water-based paint. My rule of thumb is if the primer is oil-based, use oil-based paint, if it's water-based use latex or water-based paint. There will be less problems that way. I've never had problems with latex for indoor projects. All water-based paints will raise the grain. Just plan on sanding between coats to remove any raised nibs. You have to sand between coats of poly, too, but that's to let the poly bond to itself. 

As Ken mentions, make certain to wipe off all sanding dust between coats.

[John Schaben]

What James and Ken said. I would also suggest adding a paint condition such as Floetrol to the finish coats. It extends drying time which provides more time for the paint to level and smooth out any brush strokes.. either that or a HVLP system does a beautiful job.

Just one other thing, I don't think Impervo really needs a urethane top coat. It's a furniture grade finish in it's own right.

[CB]

I have always read you can do latex paint over oil primer but not the other way around.

What is the purpose of the sanding sealer? Is it necessary? I read that it can interfere with the next coat bonding properly.

[John Schaben]

Sanding sealer is designed to help you get a level surface quickly. It fills in the tiny voids that wont show up until a top coat is applied. It also works like a stain prep because it seals the surface so you get a more even distribution of stain. Sanding sealer dries clear. If the exact tone of color is not critical you can use shelac and save some money, it will do the same job but will impart a slight tint.

Zinserr BIN is a shellac based product that works well in this application but stinks to high heaven. On the other hand, it will also take a topcoat in about 45 minutes. Automotive primer that will wet sand also works well, don't do the wet sand on wood though, just so it says "wet or dry sand" on the label.

CB said:

I have always read you can do latex paint over oil primer but not the other way around.

What is the purpose of the sanding sealer? Is it necessary? I read that it can interfere with the next coat bonding properly.

[Ken Darga]

CB,

True---latex paints can be used over oil base paints.

I wouldn't use oil-based paints over latex paints.  

Sanding sealer---

seals the wood. It fills the pores and hardens the fine ends of the grain so that when you sand it, the grain sands away smoothly. It provides an excellent base for finishes.

 If one chooses to not use sanding sealer, the first coat of your finish will raise the grain and then you have to sand off something that may be a lot harder than sanding sealer. 

  Pine does not sand evenly. Sanding sealer can help fill some of the pores in the wood to create a smoother finish. Without it, your finishes tend to be splotchy and unprofessional. Also, you should try to sand the product by hand. This will help avoid blemishes that will show up on the finished piece.

  Zinsser product literature:

>>>Rustoleum Rust-oleum Zinsser 854 1-quart Bulls Eye Sealcoat Universal Sanding Sealer 1-quart : Woodworkers use sanding sealers to speed the progress and improve the appearance of their finishing and refinishing projects. SealCoat Sanding Sealer offers time-saving versatility in a pre-mixed 100 wax-free formula manufactured using revolutionary, patented shellac. The 2-pound cut formula penetrates the surface of wood and dries quickly, giving a rich, beautiful tone to wood grain. Since it contains no waxes or stearates its guaranteed to be compatible with oil-base polyurethane, acrylic polyurethane, lacquer, varnishes, even catalyzed finishes. It seals all types of wood including oak, maple, chestnut, mahogany, walnut, birch, poplar, cherry, exotic woods, etc. Recommended for interior woodwork, including paneling, molding, trim, windows, doors, cabinets, furniture, and toys./p>

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CB said:

I have always read you can do latex paint over oil primer but not the other way around.

What is the purpose of the sanding sealer? Is it necessary? I read that it can interfere with the next coat bonding properly.

[Rick]

Today's paints allow you to use latex over oil or oil over latex, just as long as the primer has dried completely.

Most painters only use oil primer when priming bare wood to be used outside.  Priming all six sides is best.  The reason oil primer is better is the slow drying time allows for deeper penetration into the wood.

CB said:

I have always read you can do latex paint over oil primer but not the other way around.

[CB]

Well this is a desk which will obviously be used inside.

I have a can of sanding sealer, Is it better to roll or brush on, or does it not matter?

[Ken Darga]

CB,

I'd brush it on or spray it on---

it dries to fast for rolling action tools.

  If brushing, use China bristle brushes.

  Start out in small and inconspicuous areas, before proceeding to the larger surface areas.

It take a little practice, but you'll get the hang of it.

Always brush into the wetted area.

When completely dry, give the finish a light sanding, before proceeding with the top coat finish.

CB said:

Well this is a desk which will obviously be used inside.

I have a can of sanding sealer, Is it better to roll or brush on, or does it not matter?