1977 Formula F-18 transom repair

[SaltytSal]

I have a 1977 Formula F-18 (18 ft. powerboat) that is showing signs of transom repair. What I need to know is this-
does this boat have an inner and outer skin that supports the transom core? I've had one fiberglass
specialist tell me that there is no inner skin. I contacted Formula and they told me that there is both
an inner and outer skin with 3 sheets of 3/4 plywood sandwiched in between. Basically he told
me that that's how Formulas were built back then- but his answer didn't seem 100% factual. When I told the fiberglass guy this,
he became somewhat defensive and retorted- "I don't care what Formula says". Common sense tells me that
there would be both an inner and outer skin. Can anyone tell me for sure what is correct for this particular boat- I need a factual
answer so I can get some idea of what the costs should be. Due to the splashwell, it seems that the repair
should be done through the rear skin- IF AND ONLY there is an inner skin. Thanks for all replys.

 

[SaltytSal]

Re: 1977 Formula F-18 transom repair

What is the best way to repair this particular transom?

 

[ricohman]

Re: 1977 Formula F-18 transom repair

From what I have seen on other boats, the inside of the transom is indeed glassed over with what you are calling "the inner skin".
However the transom should not be replaced by cutting through the hull. It should be cut out from the inside.
Is your boat an i/o? I have seen some replace the trasom without removing the top half but really this needs to be done to make things easier.
I would also guess that the motor mounts, stringers and deck need attention. The few restorations I have helped with turned into full blown rebuilds after we started digging. Boats seem to rot from the bottom up and if your transom is rotten I would assume there will be some other rot.
Cost is what you make of it. My buddy dumped nearly $1500 into his Bayliner and its still not complete. And its been an ongoing project for over a year.

 

[SaltytSal]

Re: 1977 Formula F-18 transom repair

Hi Ricohman-

Thanks for your reply. I have a 140 Evinrude O/B

 

[metriccrescentwrench]

Re: 1977 Formula F-18 transom repair

There has to be an inner skin for structural reasons. And the proper (and easiest) way to do the repair is to remove the inner skin, then to put in a new inner skin after the new transom is in place. And I wouldn't trust a "fiberglass specialist" who says otherwise.

There are plenty of restoration threads here, in the restoration section (go figure !!). Spend some time browsing through them and you'll learn a lot.

 

[Solittle]

Re: 1977 Formula F-18 transom repair

Doo a Google on "coosa" to replace the plywood for the core. It is a fiberglass mat and I'm told it is used on racing boats. Had mine done that way years back.