What is holding on to the transom? How do these bolts stay in?

Hi. new member new to boat repair and maintenance and such.

Materials looked good for this I hope it is appropriate, I will. Need material input next.
I have a 1967 Crestliner aluminum v hull.

I hope I can get pics up showing before and after transom removal. Right now I am wondering how the bolts are attached. when removing the old transom I could not turn some and cut the head off others the wood pulled off over the top. any way the bolts are held in there. what is used for this and are these necessary for holding the transom? it is like hollow wall insrets were used. LOL maybe but thinking not.

Once I learn this I want to rebuild the transom and will need guidance on material. like does it have to be $110 a sheet marine grade plywood?
Any way first things first.

 

Welcome.
You may be dealing with T-nuts.
T-nut - Wikipedia https://en.m.wikipedia.org/wiki/T-nut

 

Here is before.

 

I would stay with marine plywood to replace marine plywood. In the long run it is still the most economical.
It must be completely sealed. If you drill a hole in it, you must seal the hole. Every time.

 

Do you have a picture from the front of the transom?

 

I don't think that was the original installation, that plywood plate looks "homemade" and in a bad way. You should investigate how it was originally intended.

 

no i did not think to do that angle.

 

i would love to. I have found it hard to even find a picture.
any ideas?

hmm. i dont know because they are stuck inside where it is all sealed off. and the bolt just spins reall lose even a wobble, but wont pull out.

 

I am pretty sure the picture shows a rebuilt transom. I dont think it was sealed with anything but paint maybe but it lasted maybe ten years? I cant ask him anymore, so just memory.

 

I would say someone made himself an extension for a long leg outboard.
As for identification and pictures Crestliner Boat Restorations, home page http://retrocrestliner.com

 

so is this significant for me? the way it was worked fine has a 40 HP johnson. do i need to know more before I rebuild same as I took offf? Why would someone do this? I am pretty sure it was this way when when my Father in law got it.
I like knowing this but I want to get it in the water soon. maybe do something different over the winter.
I appreciate the thoughts and information. I will check out that link. Thank You.

 

Which model is the boat?
Length?
Beam?

 

How about a lateral view of the boat?

 

Agreed. Mostly. It looks like someone cut off the top of the transom and then did the extension.

I will only advise the following.

Find a qualified aluminum welder and weld new aluminum plate back in after securing the boat side to keep them from deforming. Once you have two new sheet aluminum in place, install marine plywood as a stiffener and rivet on a cap. There is no way I'd ever get in that boat otherwise. Some boats are better sold to the scrap heap. And this is one. Sorry, but I'd rather be cruel now than see you swimming when the transom fails.

 

still trying to learn about this boat. I will measure it if that helps me. I will also take more pictures when the air is breathable again.