well i was avoiding the specific conversation about the construction of this
sign because i didnt want to plant any ideas in the OP's head..i just wanted him to listen to commonsense and pass on this project..and apparently he is.
Jhill i have seen more hack job channel letter jobs than i care to remember where the back of each letter is plywood ...YIKES... it is the only indicator that i have ever needed to tell a client that service and repair is not an option and that the only way i would work on it is to REPLACE it.
i have seen more single sided cabinets than i care to remember where the backside is plywood...
both of these make zero sense to me because the cost of materials to do it right is not a big factor.
the new trend i am seeing more and more is illuminated 'cabinets' made entirely out of wood...i recently spotted one being hung by a
sign company (a quicky sticky type shop) that was constructed of 2" X 10" lumber lol with the faces cut to the OD of the frame and then simply screwed into the 2X10's instead of retainer, i mean why not? if you are going to do a hack job go all the way. my biggest laugh was that they were taking great pride in this .. uhm...
sign after they attached the faces they applied approx 4" vinyl stripes over their screws to create a 'border' on the
sign...installed the
sign between two 6X6 posts set in concrete with the top of the
sign at about 8' off the ground so there might be 2' in the ground..doesnt matter either way, it is just one of the most incredible hack jobs i have ever seen...but they truly took pride in the construction, painted the 'cabinet' and posts white after installation.
there is some FRIGHTENING work being performed out there..when people in the industry get frustrated when we start talking about a self regulating professional organization to implement a system of ensuring that minimum standards are maintained...it is situations like this..where you think it must be a typo NO one would ever use plywood for the backer of a channel letter? oh yes they would ... and they do....