Friday, February 6, 2009

Asphalt Shingles for Your Dollhouse


NOTE:  The following text was originally written when a product called "What's Next" shingles were available.  At this time, this particular brand of dollhouse miniature shingles is not available.  A new product by Alessio Miniatures is currently available, but these shingles are not manufactured using the same method, so references to "15 pound tar paper" does not apply.  Also, Alessio Miniatures asphalt shingles are NOT intended for outdoor use.  The installation method described below is still very much applicable.  Should you have any questions, please contact me.

First, paint the edges of the roof the color of the shingles. You might also consider installing copper flashing.

Second, measure the first piece of shingle so that the slits in the material come out even on the left and right edges of the roof. Cut this piece off the roll. Now measure the second piece. This second piece is measured so the silt is centered between two slits on the first row. Cut this off. Use these pieces as patterns for cutting the rest. (NOTE: You have two kinds of rows, odds and evens.)

Third, make sure slits line up correctly from strip to strip. If the slits in one strip do not line up with the slits in the other strips, lay the shorter ones on the table and run your fingers along the strip to flatten and stretch it until it matches the other strips.

Fourth, glue the first strip along the edge of the roof, overhanging the roof by 1/16" or 1/8" (depending on scale). (Optional: Glue the first strip with slits facing the peak of the roof, then glue the second strip on top of the first strip with slits facing down and centered between the slits in the first row. This creates a weather tight seal on the roof edge similar to a real roof.) From the bottom edge of the shingle, Mark of dots every ¼" or ½" (depending on scale) to the roof peak on the left and right sides of the roof. With pencil and ruler, join the dots to make parallel lines. Measure accurately. This keeps shingle rows even going up the roof.


Fifth, glue rows up the roof, lining up the back of the shingles with parallel lines. Apply glue to both the spine of the strip and the individual tabs. If using staples, staple above slits, 1" to 2" from the edges, then 4" between staples. Cut uppermost row to fit peak. Cap the roof with separate shingles cut from the strip.


What kind of glue can I use? We recommend a petroleum based glue because this is a tar paper product. Construction adhesive like Liquid Nails®, lacquer based glue like Goop®, or Multi-Grip work equally well. Staples can also be used. White or wood glues are not recommended because they tend to fail after prolonged contact with the tar paper.

What are the shingles made from? Basically it is made from fifteen pound asphalt roofing paper, similar to what is probably on your own roof. The granules are made from various recycled materials, sized to scale and glued to the tar paper.

Can they be used outside? Yes, the shingles can be used for many projects outdoors. We do recommend that you protect the shingles with a coating of satin finish polyurethane paint, (either spray or brush) especially on the textured shingles. Both ultraviolet light and harsh weather will damage the color or granules. The painted shingles or plain shingles do not need this protection.

Will the color fade? Some of the shingle colors are not colorfast and ultraviolet light will fade the base color. Canyon Red and Spruce Green are the colors that fade most. Fluorescent lights do give off ultraviolet light and will cause fading. The rest of the line does hold up very well.

How many shingles are in each package? Each package will cover about one square foot (three square centimeters).

How many packages do I need? Measure the square area you are covering (length X width = square inches or centimeters) then divide by 144 for inches or 9 for centimeters and this number is how many packages you will need. If you have valleys, dormers or complex roof shapes the angular cutting creates some waste that is unusable and will need more than a simple roof, so plan accordingly.

What do I do if they curl or wrinkle? Tar paper is actually asphalt saturated felt paper and will stretch or shrink when the humidity changes drastically. To get the shingles to relax and lay flat again use a damp towel and weight, place the damp towel onto the shingles and weight them down for about 30 minutes, then remove the weight and towel and allow to dry.

Asphalt shingles by Alessio Miniatures can be purchased at Jeepers Dollhouse Miniatures.

Friday, January 23, 2009

Ohlm's Law Simplified for Miniaturists

While making sure I understood the relationship between watts, volts, amps, and miliamps in miniature lighting, particularly LED's by Novalyte, I learned this simple formula.

P = E x I

which translates into: P(power in watts) = E (Electromotive Force or Volts) x I (current or amps)

Conversely, for further information:
1,000 miliamps = 1 amp

Most of us don't really want to know about formulas, we just want to do miniatures and light them up for all to see. But understanding these formulas helps us make informed decisions regarding our lights and transformers. Another interesting formula that helps us understand the relationship between transformers and the number of lamps they can support is:

Watts divided by Voltage equals Current (or amps).

While you may not care about these formulas, I wanted to lay them out in this blog so that I (or anyone interested) could have ready access to them.

With a little algebra, you can estimate your electrical needs.

Monday, January 19, 2009

Novalyte LED's and Transformers

The average 12 volt miniature light bulb is 60 mA (milliamps). LEDs take less, with 1 LED being 35 mA and 4 LEDs being 70 mA (or almost the equivalent to one miniature bulb). The more LEDs on a line, the less power each individual LED takes. I’ve provided the charts below for reference.

Novalyte Lamps:

1 light strip, can light, or tab = 35mA
2 light strip = 35mA
3 light strip = 45mA
4 light strip = 70mA

Cir-Kit Transformers (mA as reported by Cir-Kit Concepts):

CK1009A = 10 watts (1,000mA)
CK1009B = 5 watts (500mA)
CK1009D = 40 watts (4,000mA)
CK1009C = 20 watts (2,000mA)
CK1009F = 3 watts (300mA)

To determine transformer requirement:
Combine total number of mA in each lamp that will be on one transformer

Example if you were to use 5 of the 4 light Novalyte LED lamps (5 lamps x 70mA = 350mA) you would require the 5W transformer (500mA) or Cir-Kit model CK1009B.