Making Lensboards

[erie patsellis]

for a database of sorts, try http://www.skgrimes.com/lensboards/index.htm The the more popular ones are there.

[Roger Thoms]

for a database of sorts, try http://www.skgrimes.com/lensboards/index.htm The the more popular ones are there.

I had missed this on the Grimes website, nice resource for lensboard sizes. I also have drawings for 5x7 and 8x10 Seneca boards if anyone is interested. These are the ones that have several chamfers and a small screw at the top.

Roger

[Alan Davenport]

I make Calumet/Cambo lensboards from 1/8" modeling plywood. Those boards are over 6 inches square; I'd worry about solid wood eventually splitting, not to mention getting broken if cut that thin. I paint the boards flat black inside and out, so it doesn't matter what kind of wood they are.

[Roger Thoms]

I make Calumet/Cambo lensboards from 1/8" modeling plywood. Those boards are over 6 inches square; I'd worry about solid wood eventually splitting, not to mention getting broken if cut that thin. I paint the boards flat black inside and out, so it doesn't matter what kind of wood they are.

I would not worry to much about solid wood boards splitting. I think the key is to make them three piece with tongue and grove joints. That said plywood is much less work and it is strong and stable.

Roger

[eli]

If you decide on butt joints for building each layer from narrow widths, which in this application are good enough, I suggest you use a thick, quality 'super glue' to quickly join the edges of separate pieces. Afterwards, use an aliphatic resin yellow glue, like the Titebond III I mentioned earlier to join the plys.

Eli

[eli]

Here is a quick sketch of a sanding-paper shooting board for making edges square for butt joints. Add 'L' brackets, or wood supports to the ends, if needed, to ensure it is rigid as it must be square at 90º to work properly.

Use a quality sand-paper, about 120-180 grit should be fine enough, glued on with double stick tape or aerosol glue and don't worry about any edges other than those that are to be joined. After you lens board is glued up and trimmed close to final size should you work on the outside edges.

Finally, Bees wax is a good protective finish for unpainted wood surfaces. You can make a excellent compound by taking equal parts of Bees wax, boiled linseed oil and turpentine and melt the wax into gently warmed linseed oil and turpentine, outside with no open flame, into a small glass jar, reserving the lid for storage. It doesn't take a lot of material to make this, two ounces each is plenty for a lot of compound.

A cardboard box with a black plastic bag wrapped around it and inside as well, with a pane of glass or acrylic on top will do the job as a solar oven when the sun is high.

Cheers

[BradS]

Here is a quick sketch of a sanding-paper shooting board for making edges square for butt joints. Add 'L' brackets, or wood supports to the ends, if needed, to ensure it is rigid as it must be square at 90º to work properly.

Use a quality sand-paper, about 120-180 grit should be fine enough, glued on with double stick tape or aerosol glue and don't worry about any edges other than those that are to be joined. After you lens board is glued up and trimmed close to final size should you work on the outside edges.

Finally, Bees wax is a good protective finish for unpainted wood surfaces. You can make a excellent compound by taking equal parts of Bees wax, boiled linseed oil and turpentine and melt the wax into gently warmed linseed oil and turpentine, outside with no open flame, into a small glass jar, reserving the lid for storage. It doesn't take a lot of material to make this, two ounces each is plenty for a lot of compound.

A cardboard box with a black plastic bag wrapped around it and inside as well, with a pane of glass or acrylic on top will do the job as a solar oven when the sun is high.

Cheers

good stuff! Thanks eli.

Are you suggesting melting the bees' wax in a solar oven?


For the OP....I just finished making a lens board out of a scrap of 3/8 inch plywood....next time I will pay for a real one!

[eli]

Yes, I suggest warming the bees wax and turps together, with some Saran Wrap over it, so it does not evaporate off too quickly, with the linseed oil in a separate container .

When everything is ready, stir in the oil so everything is well blended and allow it to cool, lid on.

Use it like a regular waxing product; apply with a piece of denim or cotton muslin, with a wad of cotton balls inside to make a small ball. Wipe off any visible excess and allow the waxed piece to cool. After it is cooled, it should have a slight haze. Buff it up with a clean rag and repeat; two coats should be enough. To kill a gloss effect, mix a bit of alcohol with some water and wipe the finish down lightly.

I should note that if you use wood with large, open grain, like an Oak, the wax will fill the grain and may show as a light colour. Some folks find it distracting so if you have any doubts, try it out first on a scrap piece.

Of course, if you're going to paint the backside of the board, you'll want do that before waxing the front or edges.

[goamules]

I haven't seen my method mentioned, so here it is. I use two pieces of masonite glue them together to make the light trap step. I use Gorilla Glue. Then I use contact cement to glue a thin piece of mahogany verneer over the top of the outside piece. The inside is painted flat black. You end up with a strong, flat, cheap lensboard that looks like solid wood on the outside. Mark's pergo method also looks very nice.

[Ernest Purdum]

Model shop plywood is great. It may not come in the exact thickness you need, but there is an easy answer. Nice hardwoods come in so many thicknesses that you can laminate up to whatever dimension is needed. The source I have used has a website, WWW.MicroMark.com. They are useful for other items too.