1975 Fiberglass Boat Restoration

[paulwang]

I purchased a 'boat' from an auction, called 'Photos Posted from Every Angle! - Take a Gamble & Bid Away!' Actually there are only 2-3 PS photos showing the outside. It's actually a project boat, shown in the pictures.
I decided to complete the restoration project by my self after a few days struggle.

The transom was not cut open by the previous owner, I thought I should check the condition. I cut a 2"X3" hole on the bottom right from outside. The wood is still solid. I then checked the bolt holes with a picker, found it's a little bit rotten.

I hesitated to cut the transom because too much work involved, money and time. Plus I am not sure whether I can do a good job.

I am glad I cut the transom one week later. The middle section is totally rotten, other than that, still in OK condition.

I do understand why the drain hole is not in the lowest position? The will be standing water even I raise the jack to its maximum height.

 

[kcassells]

total rehab. have at it.

 

[Scott Danforth]

Your boat is a total gut job project. If you tackle it, we are here to answer questions. However start with the DIY sticky at the top of the forum

 

[ScottinAZ]

nothing that many have not done before, some many times. If you take your time and do it right, you will wind up with a boat that is in near new condition, and will last you a good long while. There are those here to assist with questions and offer encouragement when it seems overwhelming (and it will at some point)

 

[paulwang]

Thanks for the encourage and help. I have read quite a few threads here including 1961 Lonestar Flamingo - SPLASHED w/Pics and a lot youtube videos. I remember Scott Danforth mentioned transom get rotten before strangers, which push me to cut the transom when was wondering around.

The thickness of old transom plywood is 16.7mm, I can't find a marine plywood thicker than 5/8" here, which is 15.67mm. I have to use it for my transom. I cut the plywood to make two pieces for the transom. Coated them with Bondo resin thinned with Acetone.

The boat is 16 ft long.

Brush Bondo fiberglass resin (polyester) on the rear transom shell, then lay one layer of 30 oz fabric, brush resin and another layer of fabric, brush resin, then plywood. Use clamps and screws from back through existing holes to make sure no gap between layers.
The next day, I repeat above steps to install the second plywood.

The total thickness is 37.23mm, I will apply two or more layers of fabric mat on the second plywood to finish the transom. The final thickness will be about 38mm.

 

[Scott Danforth]

normally a transom is 1.5" of wood (38mm ) and 2" total thickness (50mm)

 

[Woodonglass]

Using thinned polyester resin as a sess as let is not advisable. When it cures it will be brittle and crack. This allows water penetration

 

[paulwang]

Using thinned polyester resin as a sess as let is not advisable. When it cures it will be brittle and crack. This allows water penetration

I coat the ply first, wait to dry, then brush resin and apply cloth. It's true there will be extra resin between cloth and ply. I will avoid this in the future.

 

[Wildey]

Using thinned polyester resin as a sess as let is not advisable.

? ? ? please clear this up fro me,
thanks.

 

[Woodonglass]

As a Sealer! Poly ALWAYS needs CSM and should never be thinned! cloth/fabric gives it structural strength

 

[paulwang]

Update of my project:
installed stringers: middle one is marine grade plywood, the two on each side are pressure treated lumber. I read a lot about not using lumber as stringers, but I don't want to purchase expensive marine ply, plus that lumber sits in my garage for over year taking space.
I didn't wrap the stringers with mat or cloth, just tabbed in. too much work to wrap mat over the stringers.

From what I understanding, there should not be a lot water in the hull under subfloor. I didn't put foam in the hull. if there is water entering the hull, it will be drained once loaded onto the trailer. Installing two vents on the subfloor will help circulate and get rid of the moisture. For this reason, I didn't coat lower side the subfloor, so that water and moisture can escape from it.

Consider this as a test, I will report back if my floor or stringers get rotten in the future.

 

[Scott Danforth]

you know that the foam is structural on the boat

 

[paulwang]

you know that the foam is structural on the boat

No, I thought the foam is only for flotation purpose. Thanks for your reminder.
I laid one more layer of fiberglass cloth to most of the bottom hull, hope that will give extra structural support. I don't have plan to add foam in at this time.