The last step of the bridge cap replacement was done this morning. As you can see from this picture, pieces of newsprint were placed under the plate, but over the Plate Support Dowels. By tugging on these pieces of paper I can check to make sure that they are all touching the plate.
When I first removed the plate I found that although the previous technician had made a new block, it was only supported by the plate screws. Seeing how this block not only is responsible for holding approximately 16 tons of pressure, but also responsible for tuning stability, this was a BIG mistake. The block itself was reasonably well made, but had one flaw: It was slightly too thick. This forced the last rebuilder to actually attempt to thin it out once it was installed!
After thinning the block and sanding it smooth, I did one other little change: I used a Pipe Organ Building tool called a Toe Hole Burnisher to slightly countersink each tuning pin hole. This will insure that when I re-drill it, it won’t splinter the bottom lamination of the block.
When it was ready, and I had properly established it’s proper position, I glued and clamped it onto the inner rim. When the glue is dry, I’ll fasten it permanently into the rim using dowels (but that’s another day!)
Here’s a closeup of the Plate (with the agraffes and felt removed.)
and here’s the same picture after sanding out all the imperfections and leftover felt and glue.
After doing this to the whole plate, and washing it down with a special solvent, I reinserted the agraffes and taped up the parts of the plate I don’t want painted. The last thing I did today was to paint it with a hard shell sandable primer. Not only will this fill any remaining chips or scratches in the old finish, it ensures that the gold paint will adhere to the plate properly.