Building on glass?

[Ron]

I've seen a few references in passing to building on glass. Can you describe the process for me? Do you put the plans under a sheet of glass and tac glue the parts to the glass as required? Is parallax error a problem? What kind of glue do you use? How do you get the assembly loose? Any suggestions?

[DerekMc]

I haven't seen anyone building directly on glass.  I have several building boards which are foam core taped to glass and work great. 

[BG]

I have built solid wing gliders on glass but never a built up structure and I have never seen anyone do it. Further I have no idea why one would bother. Yes plate glass is flat but a good building board is flat too. No need for glass.

BG

[Tapio Linkosalo]

I use glass as my tabletop building board. Absolutely flat and solid. I tape my drawings onto that, using some more strips of clear packing/masking tape over the areas spilled with glue (rib/spar connections) to ease panels lifting off the board. Then I use either strips of masking tape, some weights (washers/nuts) to keep the parts in place. I mostly use diluted cellulose glue for building (or slow laminating epoxy for joining carbon parts), so my building order is to place all parts in their final place, then use a needle nose glue bottle to apply glue to the seams.

[stupid]

I've seen a few references in passing to building on glass. Can you describe the process for me? Do you put the plans under a sheet of glass and tac glue the parts to the glass as required? Is parallax error a problem? What kind of glue do you use? How do you get the assembly loose? Any suggestions?

We don't know why you're considering building on glass. Do you work or own a glass shop?

If you have a balsa wood work surface here are some tips to keep it flat.

Great Planes Pro Building Board 16x36x3/4in.
Price  $19.95  Order
 This is a Medium size 16x36x3/4" Pro Building Board from Great Planes.
      It is a flat, solid surface to build model airplane sections upon.

FEATURES: Multiple-section, finger-jointed wood construction resists warping,
            so modelers can build with greater confidence. it is sanded smooth and ready to use.

SPECS:    Length:     36" (913mm)
          Width:      16" (406mm)
          Thickness: 3/4" (19mm)
COMMENTS: To prevent warpage, this board must be allowed to stabilize in
            moisture content whenever it is moved to the hot outdoors from an
            air conditioned indoor area. This can be done by removing the
            packaging and standing the board on end for a day or two allowing
            air to contact both sides evenly. Warping can occur when placing
            one end against a workbench or face down on a table. The slight
            warping will go away in time as the entire board reaches the same
            moisture level. When one side has more moisture content it will be
            longer thus causing bowing usually in the cross grain direction.
            Once both sides reach the same moisture level, the board will again
            be flat.

Or you can just keep glass on both sides of your balsa wood building Board to keep it from absorbing moisture. Remove the glass when you need to use it for pins.  Personally I don't like using pins for some parts of building process because it slows it down.
                                                 Bob

[modler]

No pin building.

[stupid]

No pin building.

Very Nice

[Sundance12]

I routinely build on glass. Plans underneath the glass but the trick is aluminum, Jigs, these are CA'ed to the top of the glass, over the plan. The jigs are leveled and aligned with a sight level to dead flat. Makes dead flat wings.
https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=1374.msg10670#msg10670

Took this plane to the 2009 Sig control line championships as a beginner stunt.

Glass is a common tool I use quite often.

Sundance12

[NormF]

There is a method that some modelers may still use. Promoted by the Hunters and Satellite City. This system works on glass or just about any surface. Basically using tack coats of 3M 77 spray glue, you attach the plan to the glass, another light coat of glue, attach wax paper, another coat of glue, attach the wood pieces.

I’ve tried this method and it works, but I’m not a fan because of the mess it leaves.

Here’s a link to the Hunter video:
https://youtu.be/7yKRkEKmZq4

[BG]

very interesting ... thanks guys.
BG

[TimWescott]

I'm just starting to move over to building on glass.

When I'm building control line planes, I've gone over to building on jigs, with the parts held down with weights.  So you can build on any surface and it works pretty much the same.  The nice thing about glass is that a good thick piece of glass is way flatter than the dimensional stability of a wooden structure, so when you build on glass it's contribution to the overall error budget is negligible.