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exterior stain advice

Our farmhouse near the ocean on the eastern shore of Virginia needs restaining. Siding is T-111. Original stain was Cabot's oil-based opaque white. What (brand) opaque, oil-based stain is the most durable, and especially, the most MILDEW RESISTANT?

Re: exterior stain advice


You might want to read the adjoining post "solid stain issues". It has pertinent information.

I have used Cabot's stains for years with good results. You definitely want to kill existing mildew lest you encapsulate it under the new coat, only to have it return shortly. Cabot suggests you use their oil base primer if the old surface is dry and failing. If it is in relatively good shape and this is only a refresher coat, you can go directly to the finish stain. Cabot makes both an oil stain and an acrylic stain. Acrylic stains will hold up much better than oil. It does not oxidize, chalk and discolor as does an oil stain.

Whereas all good paints and stains have mildecides in them, they will all show some mildew infestation under the right conditions. Unfortunately, a white stain, as opposed to a darker color, is going to immediately show the mildew. You might unfortunately be in for almost yearly cleanings with a bleach solution. If you don't have one, you might invest in a pressure washer with a high pressure injection tip. A high pressure tip allows you to inject bleach right at the nozzle rather than siphoning back at the pump and possibly having bleach back up through the pump. It will also allow you to shoot the bleach up much higher than a low pressure tip. With such a tip it is possible to throw your bleach/detergent solution up to the gable of a 2 story house. http://www.cmcpwe.com/accessorycheminjectors.html

Re: exterior stain advice

I guess I shouldn't have specified "oil-based" in my previous post. Would a waterbased or combination stain offer more weather and mildew resistance (farmhouse, T-111 siding, near ocean)?

Re: exterior stain advice


I favor acrylic stains or full bodied paints for several reasons:
- an acrylic is more color fast than oil products
- an acrylic breathes better than an oil product, allowing
moisture generated in the house to migrate to the exterior
- the acrylic film is more flexible than the oil paint, allowing
it to better span the grain of the T-111. T-111 is basically
just exterior plywood and the grain tends to open up with age.
- an acrylic contails no linseed oil, a nutrient for mildew

All top line paints and stains contain mildecides. Using anything less than premium paint/stain is penny wise and pound foolish. Important with any paint is not to paint over active mildew. There are anti-mildicides on the market which may be added to the paint in addition to that which is in the paint.

Behr now markets stains and paints using "nano" technology. The ultra small nano particles ( a nano is a billionth of a meter) fill in the gaps in the paint film . They claim it is inherently more resistant to mildew by virtue of the fact that the film is so dense that the mildew has a difficult time getting a foot hold. There is also a chemical mildecide in these stains and paints which are marketed under the "Ultra" label.

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