Shellac for Exterior Priming
Shellac isn't recommended for outdoor use. But some people report that they've gotten away with it. June 18, 2009
Question
Has anyone had any experience with fiberglass? If so what was the best method for staining? I have tried just wipe on wipe off with a brush but the color comes out real light and when I go back over with second coat to achieve darker color it reactivates the gel stain and I end up with the same lightness of color.
Forum Responses
(Finishing Forum)
From contributor G:
I sprayed the stain as a toner and then cleared with a water based exterior poly.
From contributor D:
To use your method of application with a gel stain (oil I'll assume) you would need to wait for the first coat of stain, regardless of color, dry before the second coat would be able to lay on top of the first coat without reactivating it. This will usually require two days of drying for oil based finishes where any type of rubbing or wiping are involved. You can speed the process up if you were to use isolation coats of sealer in-between such as shellac. I would opt for some sort of shading technique.
From contributor G:
Shellac should not be used for exterior applications.
From contributor R:
Use a dry brush technique when apply the stain.
From contributor D:
Shading can be done with dry brushing, wet ragging or spraying. Although shellac is not recommended for exterior use, I have used it with great success in exterior use as long as the door is well protected from the elements and I make sure to seal all surfaces of the doors, especially the top and bottom edges. You will also need to find a finish that will adhere to the shellac such as, water dispersed poly.
From contributor A:
BIN shellac primer is rated for exterior spot priming. I've used it on my own property without top coating it for a couple of years on cedar. It holds up better than some topcoats.
From contributor G:
I use to use the bin as a primer for doors and entryways. It was easy, went on great and dried quick. But I didn't want to take the chance that it would fail. It is not designed for large areas because it doesn't stretch, which is required of exterior coatings. I know where you're coming from. But shellac is not really an outdoor coating. I've learned from my mistakes and that was one of them.
From contributor D:
Shellac is not intended as an exterior top coat! It can be used as a primer coat in exterior situations, but is only recommended for spot priming because of Shellac's lack of flexibility. Even Bin white shellac primer should not be used to seal the side of an entire house, even if top coated. The paint will literally pop off the house in huge pieces when the wood goes through its natural expansion and contraction cycles. The shellac that I recommended in a prior post is essentially the same, de-waxed shellac Bin uses in its primer formulation, only in it blonde (light) clear formulation. Once top coated the shellac is essentially a non factor in the finish schedule.
From contributor A:
I agree that you should not use BIN for anything other than spot priming or 2' x 2' areas. However, after my own experience I don't believe the peeling theory. At the end of the day the shellac in BIN is so reduced that it is a sealer, not your typical film finish. Once again, I am not recommending anyone paint their whole house with BIN.
