Question: When I look at the edge of my power module firewall, I can see small gaps between some of the laminations. Is this normal? Is it OK? Is it coming apart?

Answer: Yes this is normal. Yes it is OK. No it will not come apart.

Expanded Answer: The power module wood firewall is made from 2 or 3 plywood layers that have then been laminated together with epoxy to produce a firewall that is approximately 1/4" (6mm) thick. There will be a wider gap between the plywood pieces than between the individual plys within a plywood piece. This is normal. The power module firewalls are extremely strong and are held together in operational use not only by Epoxy but by four engine mounting bolts and four power module to fuselage stud and nut sets. This represents 8 mechanical fasteners in addition to the epoxy between layers... all acting over an area less than the size of a dinner plate.

Short of a very violent crash the power module firewall is not going to come apart. Small gaps or voids in the plys or in the bonding layer between plywood pieces are not going to impact on the performance of the power module firewall in our application.

If you are wondering about sealing the power module firewall, please see below:

Question: Should I seal the wood power module firewall that came with my VMAR ARF?

Answer: It's not really necessary but it probably can't hurt aside from adding a bit of weight. If you have an hour or so and the right materials, you can improve the cosmetic appearance of the power module firewall by sealing it.

For those who wish to seal the edges and faces of the power module firewall, we recommend Pacer ZAP-A-GAP CA+ for filling edge voids or edge gaps between layers and then after the CA+ has cured, apply Pacer Finishing Resin to the edges and the front and rear faces of the firewall.