Anyone ever use polyurathane spray on raw wood?

[handibunny]

I'm wondering if, on an urn made of aspen, with enough fretwork to make me not want to rub or brush on several coats of shellac, it's OK to spray a coat of polyurathane directly on unfinished wood. I usually use several coats of shellac, then several finishing coats of polyurathane. It's a delicate piece, so if I can just spray it to give it some shine and a more finished look than raw wood, I'd rather. Anyone have any experience with this? Thanks.

Carole

[workin for wood]

sure you can do that. Personally, I'd use an oil finish first such as danish, tung or teak oil and let sit for 3 days before spraying. The main reason being that it is easier to get the oil to run down into the little fret spots and then you can wipe of the surface. If you simply spray, you'll be spraying in several directions to try and get into the holes which will cause too much spray on the flat surfaces which is sure to cause runs that need to dry and be sanded down and re-sprayed. I still think you should spray, but oil first, 3 days then spray light coats.

Use a small handled sponge to help squish the oil in the holes/frets.

While your waiting a few days on that finish you can still do other things...dust won't be a big issue on the oil finish after an hour or so of dry time. Build yourself a nail board to spray it on. just get a scrap of plywood and drive several nails through it...a air nailer works easiest and fastest. Turn the board over so the nails all point upwards, the more nails the better. Set your project on top of the nails to dry. You can spray the object while it is on the nails...spray the bottom first, then set on the nails and spray the rest. The wet finish on the bottom of the project will barely be affected by the nails, and it will dry with even airflow. (be sure and sign your art before you finish it).

[MacS]

Shellac under Polyurethane?

If you use shellac under Polyurethane, you must use "dewax" slellac.

Many manufacturers of Polyurethane prefer that you "do not use shellac" as the sealer under their Poly.

Here, is a suggestion that you should consider.

Reduce the Poly by 50 % with Mineral Spirits and use that as your sealer coat, allow it to dry, and then use the Poly at the reduction that on the container.

Polyurethane is a high solids coating. it may contain 45 % solids (resins) that makes it a high build coating.

Good Luck

[lucky788scroller]

Since your wanting to use spray, Im assuming aerosol, I dont think there would be a problem. I do think dipping in Danish oil first would be a better choice, or a thinned polyurethane, as Mr.Finisher stated. Then aerosol should be fine. Sanding tween coats may prove tricky if its a fragile piece, but should really be done. Dale

[Minnesota scroller]

Is the sole purpose of the poly spray, just to give the wood a shine?

[lucky788scroller]

seal, shine, and protect for me

[handibunny]

Thanks, everyone, for the suggestions. Regarding the need to use dewaxed shellac, I make my own shellac from wax-free flakes. (By the way, from my cake decorating days, I've made shellac witb grain alcohol as the solvent. That's a perfectly food-safe product, without having to wait for solvents to evaporate. Grain alcohol has other uses, too . . . ) I like the idea of using oil first, since it's so practical with fretwork. I'll try a poly spray for shine, since the aspen I used (prototype--will make the next one with maple) looks kind of dull with just wax.

Thanks again.

Carole

[MacS]

Vodka, any one?

Carole,

Many finishers use ethyl alcohol for both doing their french polishing, and for brushing on their shellac coatings.

Some, finishers buy their "grain alcohol" at the liquor store. It certainly is safer.

[Mick Walker]

(be sure and sign your art before you finish it).
Jeff said to sign your work before you finish it. I usually apply one coat of finish to seal the wood before I sign my project. Signing the bare wood the ink bleeds into it. I use a Parker roller ball pen.

[workin for wood]

good point mick..a roller ball or any ink pen might bleed. I'm using a special thin tip black marker from an art store that does not bleed on raw wood nor will a finish smear it.

[GrayBeard Phil]

OT: Shellac finish

Mac:

This is way off topic, but if I may:

With regards to grain alcohol with shellac-Have you ever heard this before:

My Grandfather told me that when he was a young man, way before WW-I, he did some work in a furniture repair store for a short while. Being in the Detroit area, Windsor, Ontario is just across the Detroit River. There is a big whiskey maker in Windsor. Sometimes after aging the whiskey in a barrel, something goes wrong and the whiskey cannot be sold (or should not be consumed by humans.) But the whiskey has this golden tint caused by the aging of the whiskey in the charred oak barrels.

Anyway this reject whiskey was coveted and much prized by furniture restorers and furniture makers in Michigan to make a shellac finish with. The amber color mixed well with the natural amber of the shellac.

No one has ever confirmed that story for me. Ever heard of using aged whiskey straight from the barrel for shellac? I think most packaged aged whiskey is watered down after coming out of the barrel as it is going into the bottle, so bottled whiskey would have too much water to make shellac today from.

Phil

[MacS]