Recreating a "Wood" Rosette

[John Pariseau]

At my church (built in the 1800's), the pews have 'wood' rosettes on the side:

front.jpgside.jpgbottom.jpg

We are missing quite a few, so I am looking into recreating them. Originally I was going to get a 3D scan made and CNC route replacements out of a piece of hardwood, but when a couple were found it the closet, it appears to be sawdust+glue and a smooth coating. I don't trust the stability of additive rapid prototyping, so I think I will make a mold of the rosette and duplicate it that way.

I'm wondering a couple of things:

1) What kind of modern-day materials (glue? resin?) could I use to recreate this?

2) Does anyone know what kind of process would have been used to make these? I don't know if they are original or not. The back looks like a rough MDF - but finer than a Sauder chipboard.

I hope this isn't too off-topic!

[Mel Fulks]

Composition has been used for a long time .I would not worry about using what the old ones are made out of .There are some excellent modern products.Basicly you use a silicone to make a mold off one of the originals,pour a casting material into the reusable mold, and then put faux finish on them. There is lots of information on line. First thing I would do is ask if a church member is familiar the process,there is a good chance some one will step forward. You are wise in accepting the fact that the originals are not wood and it's fine. Good luck!

[Bill Edwards(2)]

These guys sell casting resins and the molding materials.

http://www.goldenwestmfg.com/

[John Pariseau]

Composition has been used for a long time.

That's what I was looking for - I wasn't too sure what I was googling for. I'm first going to make the mold, then a positive to clean up.

[John Pariseau]

Just wanted to post an update

I went ahead and made two molds - one for the small size (had to turn a short pew on its side :P), and one for the medium size. Having trouble, however, casting it. Rather than resin, I decided to use Durham's Rock Hard Putty. Why? The material is non-toxic, and was on-hand and easy to prepare.

However, I'm getting bubbles in the finished rosettes. I tried mixing a thin batch and painting it on - that ended up creating a rougher texture - and it still had bubbles. I don't have a vacuum chamber to suck the air out of the mixed putty - any ideas? I really like how it turns out - the resulting rosette seems durable and probably will last a long time.

Thanks!

[Mel Fulks]

With that much thickness I would be surprised if they don't get cracks before long. If they don't ,I guess you can just fill the bubbles. The materials made for casting work well even without vacuum .

[Peter Quinn]

Vibrator. Not sure what you have on hand, I've heard of guys using an impact driver, an oscillating tool with a flat blade, a neck massager. I use to make septic tanks, same idea as the rosettes, just bigger and less elegant. We had giant vibrators that hooked up to the tank, shook all the air bubbles and voids out of the mix, shook all the blood out of your hands too! My wife has this pair of massage "boots", you put your feet in, gives you carpal tunnel of the toes in under 10 minutes. Bad idea for foot pain, might be just the thing for filling molds if you cut the boots of and used the base. I also worked as a chef for many years, used to watch the chocolatier make the fine chocolates for a hotel, basically you fill lexan molds with chocolate, let it set, fill with what ever the filing is, put it on a vibrating pad for a few minutes, settles in nice, all the voids go out, top it off to replace the air that left. Not sure where they got those vibrating pads, they were roughly 12X12, high oscillations, not to bouncy. Its a bit like making concrete counter tops too, the vibrations seem to pull a thin layer of very moist slurry toward the bottom of the mold, or toward the vibrations, leaves a very smooth surface.

[John Pariseau]

I tried using a flour mixer, but it wasn't strong enough. I have an oscillating tool, but I'm unsure whether I'd want to run it for very long - could try that. The mix is thick.

As for cracks - hrmmm. I suppose it could crack, but I tried breaking one of the ones I made and was unable. The stuff is pretty hard...

If I have to I'll resort to resin. Supposedly I can mix pecan shells with resin to darken the mix (though they will be painted, my concern is chipped paint).

[Ernie Miller]

When the resin has cured, the resulting casting will be quite shiny and slick - usually too slick for paint to stick well. Before pouring the resin into the mold, spray the mold with a mold release agent. Then sprinkle a generous amount of talcum powder onto the mold. Blow off the excess with compressed air, and pour in the resin. When it cures, the casting will be matte instead of glossy and the paint will adhere much better. I get my casting supplies from Smooth-On and they have a lot of info in pdf format that you might want to take a look at.

[Russell Sansom]

Random orbital sander? The butt end of an Electric toothbrush? "Personal" massager. A stick with notches, stroke the notches like a cricket noise maker? The mind reels.

[Robert LaPlaca]

John, there is a company named Decorators Supply in Chicago that makes composite carvings, you might want to check out their catalog of round rosettes here http://www.decoratorssupply.com/stor...oryBody&c=CRRC, I lost track at more than 20 pages of round rosettes. I believe their composite carvings are made of wood shavings and hide glue reinforced with burlap, in the same fashion as the existing rosettes would be in the church..