Both Examples:  Preparing for and creating a pattern

NOTE: THIS CHAPTER IS STILL IN PROGRESS

Up to this point, the Example 1 and Example 2 have been different enough to justify separate sections.  From this point on, the processes are nearly identical. 

Step 9:  Toughen up the surface

There are two reasons that you’ll want to toughen up the surface of your lampshade form: 

1. The Styrofoam is very crumbly and, unless something is done to stabilize it, will fall apart as you continue to work with it.
2. The Styrofoam is too soft to hold a pin for any extended period of time (remember my requirement that my lampshade form material be able to hold pins).

I experimented with polyurethane spray and white glue before I found a combination that I was happy with. 

• Polyurethane spray stabilized the surface (i.e., made it so it wouldn’t crumble) but it didn’t do much to improve the Styrofoam’s ability to hold pins.
• White glue improved the Styrofoam’s ability to hold pins but the application process (spreading with a paintbrush) crumbled the Styrofoam.
• *The solution that worked best for me was to apply a single coat of polyurethane spray and, once that was dry, paint on the white glue.

I actually found that 2 or 3 coats of white glue worked best.  In subsequent steps, we will be gluing a paper pattern to the lampshade form and then applying another coat of white glue.  For that reason, one coat of white glue will do at this point.

Step 10:  (Optional) Damage repair

At the end of Example 1 Step 6, I mentioned that my lampshade form had some major divots that I wanted to repair.  This was something that I hadn’t had to deal with before and, even now, I’m not entirely sure that repairs were necessary.  Before each form is finished, I’ll be completely covering it with a paper pattern and sealing that with a coat of white glue.  That in itself would cover the divots.

In any case, this optional step addresses the filling of those divots before we get to that pattern step.

In determining what it was that I wanted to use to patch the holes, there were several considerations:

• The patch material needed to be able to hold pins.
• Sandpapering could not be a part of the process.  In past projects, I’ve found that Styrofoam is softer than just about anything that you might use to patch it.  Any attempt to sand down a patch is most likely going to leave the patch unchanged and remove some of the Styrofoam around the patch.

I decided to go with latex caulk.  It’s water soluble so, with a wet rag always on, I can easily use it to fill the voids and then smooth the surface with  wet finger.  I found that several applications were needed.

You may be able to come up with a better alternative.  Since the patches are going to be covered by the pattern and glue, the patch material doesn’t need to be something that will ever completely dry.  It’s occurred to me that, if I was going to do this again, I might try plumbers putty.

Step 11:  Draw the repeat lines

At the end of Step 3 (in both examples), I had a wood base for my lampshade form.  On my base, I had drawn my repeat lines.  Since those repeat lines would eventually disappear under Styrofoam, the last thing that I did in Step 3 was to mark the ends of the repeat lines on the edge of the wood base. In this step, I’ll make use of those marks.

In the case of Example 2, the inside form, the marks on the wood base needed to be transferred to the top outside edge.  The squared sides of my wood form made the perfect tool (I could have just as easily used a roofing square).

Example 1: Transferring lines to the top edge

 I’ve done some pretty crazy things in the past to draw the repeat lines on my finished forms.  I won’t go into detail other than to say that my process involved a plum line, two carpenter’s levels, a dark room and a laser level.  With all of that, the result was marginally adequate.

This time around, I knew that I needed a simple process that would yield a decent result.  Early on, I recognized that I already had a nearly perfect tool for drawing those lines.  The wood profiles that I created to shape the forms were the perfect shape to help me draw the repeat lines.

The only issues that I had to address with those templates had to do with the pivot pins. When I was shaping Styrofoam, I needed to be able use a chopping motion.  To support this I made pivot pins that were short and rounded. 

Short rounded pivot pin
(upper left corner)

When I use my template as a guide for drawing the repeat lines, I’ll need to have it stand perfectly upright.  I’ll need a pivot pin that is longer and straight.

Note about copying:

There’s one thing that can be very difficult when you go to make the multiple copies that you’re going to need of your lamp pattern.  You will always want to make certain that your copies are exactly the same size as your originals.  Many (most) copiers will change the size slightly.  The test to see if this has happened is to put the original and copy together and hold them up to a light.  If the original and copy are the same size, you’ll be able to align the images.

The first time that I did this, I used a copy machine that allowed me to set a plus or minus percentage to tweak the size of the copy.

The second time, I scanned my original to a .pdf file and then printed with a laser printer.  The default page scaling setting was “fit to printable area” which sounded like it was asking for trouble.  I changed the page scaling setting to “none” and gave it a try.  Fortunately, it worked perfectly.

If it hadn’t worked perfectly, I probably would have tried scanning to an image file so that I could use Microsoft Paint to stretch or shrink the image until it printed the correct size.