1963? Hydrodyne custome deluxe 1700 restoration thread

So you are using plywood as a core in the stern 1/3?

 

See post number 120.

jim

 

my phone does not display post numbers. I am still on vacation and so computer less.

 

thanks Brian you're the man. I am still wondering if there are any voids between that plywood core and the hull

 

yes I am using the plywood. I am sure there are some voids, there will be with any sheet style core like plywood or foam. I was trying to limit it some. Guess I could have drilled holes in it like a peg board to allow the resin to flow up through, but too late. The good thing is if there are any voids, they should be small. That and there is an additional two layers of glass on the bottom of the boat. The old core had tons of voids, I think this one is better and the glass is more solid now. Worked for the last 50 years, this one should out last me. i debated it for awhile, but the pros of using the ply won out.

The plywood now has a layer of mat over it and a layer of roving over the back half. That will be about it for a couple weeks before I can work on it again.

 

Both of you are using some innovative techniques in the restorations. I am eager to see how it all shakes out.

I think using the plywood to keep the bottom straight is a good idea.

We did have a member restore a boat using planks (not balsa) a while back. He was not real careful about bonding them to the outer skin and I think he had big voids. The symptom was a lot of vibration at speed. I think it could have been fixed, but he disappeared.

jim

 

Brian - what is the stringer plan? how are you going to mount that motor to the floor in the stern? I have no experience rebuilding a stern drive boat but I am sure you have a very good plan considering your past job.

 

Not positive yet. The boat will have a brand new transom, so I can go with the stock design if I want. On these old Volvos, the outdrive mounted to the transom and the motor mounts into that. Nothing touches the floor of the boat on these 1.8 - 2.0 L engines. That being said, the blocks do have attachment points for mounts (standard car location) and later Volvo engines I have seen with other stringer mounts. So I can go one of two ways: Leave it suspended by the transom assembly as they were done at least into the mid 70's, or add some short stringers / knees to help hold the motor and stiffen the bottom further.

If I go original, I will still add a couple of smaller knees to help tie the hull into the transom. They will not go further forward than the firewall to keep that original looking. The placement is mainly limited by where the fuel tank goes on the starboard side next to the engine. Forward, I am going with side benches, so I am going to build those in with storage for jackets / paddles underneath that. That will provide two stringers that will be glassed into the hull bottom about 36" apart and run to the firewall. To these seat bases, I can add a cleat and a short stringer over the keel to support a piece of 1/2" plywood that will be the 36" wide x about 6' long. This will be removable .

If I go the latter route, I am planning on a couple of smaller knees that will run from the transom up about 3 feet. I would have been more concerned about some kind of print through into the hull bottom with a balsa core, but given the extra glass and plywood in the hull bottom, a simple 3/4" wood stringer should work well. The old setup felt absolutely solid so anything that ties the front of the motor into this structure will just be bullet proof. I do not want to add too much weight though and it will add up fast.

As long as the engine checks out fine, I am going to purchase the AQ130 motor I found that comes with a 270 or 280 drive. It is still on the cut out transom of the old boat, so I have a sample of how it was mounted and a template to use. Given that these boats originally ran with an 80 HP inboard, the 130 will be more than enough even if it is a bit tired and I add a couple hundred extra pounds. Still less than the water that was soaked into the old core!

As I get closer I will do some cardboard mock ups and post pictures.

 

You might want to consider a forward mounted fuel tank for balance.

jim