Stain color too dark on our fiberglass door.

Questions & AnswersCategory: Fiberglass Door Finishing QuestionsStain color too dark on our fiberglass door.
Laurie asked 8 years ago

We just stained our fiberglass Thermatru door and the color is TOO DARK. We have not put the topcoat on yet. Can we lighten the color a little bit? by using the lacquer thinner? OR?

The Thermatru door has been nothing but a NIGHTMARE!! they are crazy charging a fortune for it and then expecting people to stain it themselves!!

4 Answers
Crowder Painting answered.

Lacquer thinner will remove the stain, just like a paint stripper. It will not lighten the stain. The only way to lighten the stain is to remove what stain is there and apply a new lighter color.

Go ahead and remove the existing stain. I recommend you do this outside and with the door on saw horses. This will make everything easier, plus lacquer thinner has a very strong solvent smell.

Use plenty of clean rags and have a 5 gallon pail filled with 2 gallons of water for the spent rags. When a rag is saturated with thinner and stain put it into the water and keep it there until your ready to put them into the trash.

It is helpful to use a nylon scrub brush while removing the stain. This will help get it out of the "wood grain" and give you a clean new surface to work on.

I recommend you use Old Masters Gel Stain for this project. They offer a neutral non-colored base that can be mixed into their gel stains to lighten or reduce the amount of color that is applied. This makes life a little easier.

Hopeful answered.

We had the same problem with the contractor who hired someone who did NOT know how to properly use the ThermaTru One Day Stain.  The color we purchased was Walnut; it came out like a dark Mahogany color.  Top coat has been put on.  We also have side lites. Does anyone know how difficult this might be?  Just need some tips before tackling this project.  Our contractor thinks it looks fine; I however, did not want stain this dark, which is why we purchased  Walnut, not Mahogany.   If it had been applied correctly (rubbed in with a cloth and not painted on with a brush) it would have been fine.  Any suggestions would be welcome. Thank you!

Karl Crowder answered.

Color intensity can be controlled, even with a brush, by pulling small amounts of stain down the surface of the door.  You are correct that “painting” the stain onto the surface will add too much stain and therefore too dark.  Check out this article for tips – https://www.house-painting-info.com/articles/staining-a-fiberglass-door/

Using rags is also possible but more difficult, in my opinion.  It can create a more blotchy look as the stain doesn’t soak into the surface but sits on top.  A combination of brush and rags is good, remove excess with the rag them blend with a dry brush.

At this point it is too late for the main door as a clear coat was applied.  The only way to lighten is to strip off the clear and stain and start over.  It is best to match the sidelights to the main door for a please overall look.

MagicDave answered.

To begin with I would NEVER use stain on fiberglass because fiberglass will NOT properly ABSORB stain… like wood will! Instead use regular Paint… So now in your state of progress I would recommend Priming it with a Pigmented Shellac and then Paint it using a color similar to the color of the stain that you originally wanted…
If you just can’t live without the “grain look” that stain gives then you could instead of just painting it, you could Antique it by using the paint along with various application tools that are commonly used for Antiquing surfaces…
SEE my pages on Antiquing here: http://www.davmagic.com/repairs/PAGES15.html
Good Luck!

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