Justin,

The first photo shows lamination of the front piece of plywood face....1/8" + 1/16" to form 3/16" thick circle. I simply didn't have 3/16" aircraft ply on hand.

The back ply face remains as 1/8" thick stock

The balsa spacer is several rings of 3/32" balsa with vertical grain. They are first formed and then epoxied together with a layer of 2 oz glass cloth between the layers. Forming is simple....wet the balsa and set it over a roll of tape, wrap it tightly with an ACE bandage and let it dry like that. Then come back and epoxy the assembly together.

Once the two ply faces are built and the balsa spacer is built, the whole thing is epoxied as shown in the second photo.

Once the glue cures, place magic marker alignment marks on the wood and cut the balsa spacer in the middle with a band saw. This cut will form a front section and a back section. It is these two section that the rubber separates and isolates from one another. That's what gives the mount its isolation capability. The balsa in the middle with then have to be sanded flat to allow the two surfaces rotational freedom.

Then proceed with attaching the blind nuts and bolts to the front face and drill the mounting through holes to both front and back plates. If your actual engine mounting is different, adapt whatever you need to the front face. For example, on other mounts for engines with mounting lugs, I epoxy maple bearers to the front face

Now, on to how the doughnut is attached to the firewall. Remember to drill the back only enough to accommodate the mounting bolt you intend to use. You will need to relieve the front face and balsa space as needed to accommodate the head of the bolt you intend to use. You must start small and then relieve as required otherwise the doughnut will not be secured to the firewall.

hopefully the instructions are clear. If not, we'll discuss them until they are

MattK