1990 Alumacraft Trophy 170 transom/floor

[DustyMiller]

Hello all, I am new here and looking for any helpful tips/ advice. Last year my Girlfriend and I Bought our first boat. After a little wrenching (my forte) got the old Mariner 115 running great. Full summer use last year, and one trip to Devils Lake, where things got windy and wet. by the end of the week found our transom was shot.... Contacted my local boat repair and found out they new this boat.. and had previously estimated the job at $4000. Which is more than we spent on the boat. Now that spring is in full swing in MN I am starting the long dreaded project.... I have gotten the engine off, and batteries out all the accessories are removed from the stern and the support pieces from under the "splash well" not sure the proper name. I am wondering will i need to take the gunwales all the way off? or can i get by with removing the back half? I am also going to be replacing the decking from the stern to the consoles while its apart. The wiring i found was terrible and I intend to replace that while I am at it. recommendations on what wood for the floor and transom build are welcome thanks in advance

 

[Emerger]

Hello all, I am new here and looking for any helpful tips/ advice. Last year my Girlfriend and I Bought our first boat. After a little wrenching (my forte) got the old Mariner 115 running great. Full summer use last year, and one trip to Devils Lake, where things got windy and wet. by the end of the week found our transom was shot.... Contacted my local boat repair and found out they new this boat.. and had previously estimated the job at $4000. Which is more than we spent on the boat. Now that spring is in full swing in MN I am starting the long dreaded project.... I have gotten the engine off, and batteries out all the accessories are removed from the stern and the support pieces from under the "splash well" not sure the proper name. I am wondering will i need to take the gunwales all the way off? or can i get by with removing the back half? I am also going to be replacing the decking from the stern to the consoles while its apart. The wiring i found was terrible and I intend to replace that while I am at it. recommendations on what wood for the floor and transom build are welcome thanks in advance

You only need to remove as much as is needed to access what you plan to replace. As far as wood goes, most any plywood will do. Match the thickness of the original. Pressure treated is best but on an aluminum boat but it's a good idea to paint any aluminum surfaces that will contact the pressure treated plywood. Some pressure treated plywood can cause aluminum to corrode. If your original floor and transom are screwed down use stainless steel screws to replace them.

This is a video of a guy replacing a transom in an aluminum boat:

After you do the first one you become an expert.

 

[jbcurt00]

Best rule of thumb is never Pressure Treated, esp not in an aluminum boat, painted or not.

 

[jhande]

Would it make sense or would it be over kill to put at least a couple of coats of fiberglass resin on the wood first?

 

[jbcurt00]

Fiberass resin? No such product, technically

Either Polyester, Vinylester or Epoxy, not simply resin

 

[jhande]

Fiberass resin? No such product, technically

Either Polyester, Vinylester or Epoxy, not simply resin

My bad, been a long day.
Meant Polyester resin. I'm using lot's of it for my stringer/deck rebuild and will be replacing my transom too.

 

[DustyMiller]

Fiberass resin? No such product, technically

Either Polyester, Vinylester or Epoxy, not simpl

Fiberass resin? No such product, technically

Either Polyester, Vinylester or Epoxy, not simply resin

i was going to seal it with some sort of resin after reading some more. any suggestions on which would be best?

 

[DustyMiller]

turned into all the floors, and im going to have to repour the closed cell foam, any recc on weight ?

 

[jbcurt00]

Epoxy is preferred @ aluminum boats

2lb pour in foam

 

[DustyMiller]

 

[DustyMiller]

Epoxy is preferred @ aluminum boats

2lb pour in foam

thank you, on the upside i get to fix all of the previous owners less that optimal wiring.