Clock face

[tkovacs]

V-Carved, MDF, 10" square

2007

[scottbot]

Cool.
I like that.
Good job Terry.

[mikeacg]

Terry,

Very nice! You have given me yet another idea to try. I love this forum!!!

Mike

[phil_o]

Very nice.

[myxpykalix]

Terry,
Is that regular mdf? How do you plan on finishing it? Very nice...

[tkovacs]

Yes - just regular old MDF. Shellac applied until the cut surface was saturated. Has been spray painted ivory and will leave it as is - let the carving have the spotlight.

Thanks for the comments!

[myxpykalix]

Please explain the reason for applying the shellac to saturate the cut surfaces then over top that painting it? Will you put something in the carving to accentuate the numerals and design? Do you have a pic of the finished piece?

I am not experienced in applying finishes so i would think that applying shellac first would prevent the paint from penetrating the mdf and just laying on the shellac base?

[tkovacs]

Well - to start I am no finishing wizard.
Shellac was applied before the cut was made to help harden the surface and reduce the "fuzzies" on the cut surface. I have not tried a with and without test so I don't know how successful this is but it seems to be working.

You are correct, the shellac does prevent the paint from penetrating the surface and that is its second purpose. Without the shellac, spray paint just disappears into the MDF requiring more coats of paint. The other plus side of shellac is that it dries quickly, ~15 minutes, and the dried surface can be touched up with an alcohol damp rag if you have made a mess.

After the cut, I soak the exposed surface with more shellac before the paint is applied.

This is a work in progress and I am thinking about highlighting. The monochrome surface looks more dramatic in person. I have painted another in flat black which looks even nicer but is harder to photograph. The finished product is a few weeks away but I will post some pictures.

[myxpykalix]

\l/
0

Thats my version of a light going off! Now I get it, you are putting enough shellac on to penetrate way deep so that the inside of your carving will have been soaked with the shellac making the fibers stiffer (even the ones not yet cut, below the surface) right?
I always thought that you shouldn't put shellac underneath paint or stain because the paint wouldn't have anything to hold on to...

I made some wainscoting that i had to paint and i used a flat white primer then white paint but it felt like i was trying to paint a sponge.

[porscheman]

Jack,

Shellac is one of the most commonly used "barrier ocats" or sealer coats because nearly anything will adhere to it, including paints, stains, and most clear coats. Shellac is often used as a sealer under paint because it will prevent bleed-through of any resin or pitch in the wood. Also, when you are refinishing or recoating a project, shellac can be used as a barrier between the old coats of finish and the new ones you are applying.

As you mention, some stains will not work well if shellac is applied first, not because the stain doesn't stick to the shellac, but because the shellac fills the pores in the wood that the stain would have filled, so it doesn't look as dark. In fact, you can often use a light coat of shellac on the end grain of wood before staining so that it doesn't soak up as much stain as the other areas of the project - this gives a much more even appearance to the stain coat.

Obviously there are many other caveats regarding all these points, but in general terms, shellac is one of the most versatile finishing products that you can use, plus it's quite easy to apply via rag, brush, or spray.

Hope this info helps.

John

[myxpykalix]

Does the same apply to polyurethane? My thought is that shellac is more of a flat more pourous coating whereas polyurethane dries to a harder less absorbent coating and is used more for a coating over whatever finish you use to protect it, am i on the right track?

[toddmaci]

Terry,
Very nice work.

Todd

[tkovacs]

Thanks Todd.

Jack - I do not think of shellac as porous, rather just the opposite. As John indicated it is used as a sealer to keep unwanted stains from bleeding into a paint layer applied over it. I use it often as a first coat to wood projects before I polyurethane. It seals the wood, does not raise the grain and dries really fast. It also gives the wood a real nice honey color too.

Terry

[myxpykalix]

and who ever said "you can't teach an old dog new tricks?"...see i learn something new every day. I will try this on my next project.

Since i have a lot more poly laying around could i use poly on my under coat to saturate the mdf, cut it, use a gel stain, then overcoat of poly?
And for the undercoat that is used to stiffen the mdf does it make a difference if you use a satin finish poly then the overcoat is a clear gloss?

[tkovacs]

Jack -
All good questions. I use water based poly a lot and it is thin too - takes a bit longer to dry though and I am always anxious to move along...

I've mixed and matched all kinds of finishes - usually without issues. Guess I would be more careful if the piece were for exterior use.

[myxpykalix]

Thats all good information that i will "put in the bank" for my next project. Hopefully i won't forget the combination to the safe! Thanks..