A Little Transom modifing

Jamie 10017 · Sep 8, 2011

I have a Wellcraft Gran Sport that I want to make a walk thur transom. Im a newbie to the forums and would like some input on the best way to box in the opening .
The boat Is a V drive and the transom is hollow where I want to cut a put the door. Im not getting any younger and climbing over it is getting to be a pain Thanks in advance Jamie

produceguy · Sep 8, 2011

Re: A Little Transom modifing

Can you post some pics so we know exactly the area your talking about?

Jamie 10017 · Sep 8, 2011

Re: A Little Transom modifing

This is what I want to do. This is a picture of a later model Gran Sport

This is what I have. The transom on this boat is 12'6" wide , Thanks Jamie

produceguy · Sep 8, 2011

Re: A Little Transom modifing

That looks like a job for the pros. Can you get an estimate from a shop, if the price isn't to bad go for it and it will be and look like a pro did it but if you just want to do this yourself I'm sure you can.
Pics of the inner transom would help also.

OOPS and Yacht Doc should be able to walk you throu it along with the other members on here. Do you have any carpentre skills, Have you done any glassing, Have You ever gell coated anything? These are all skills you will need to have or learn.

Welcome to iboats Jamie

Jamie 10017 · Sep 9, 2011

Re: A Little Transom modifing

Yes I have done some glass work and some wood working before also, I will post some more pictures of the inside under the transom, Thanks

oops! · Sep 9, 2011

Re: A Little Transom modifing

hi jamie....welcome to iboats....

we need to see whats under there and your current interior configuration. this will requier a lot of fabbing...but anything can be done.

i have not dont that exact job yet, so i would need to think about it for a wee bit. just off the top of my head, the cap hull joint in that area would either need to continue thru the passage or be erased by fabbing. that particular area takes a lot of stress. so any fabbing would need quite a few corners to keep the transom rigidity.

Jamie 10017 · Sep 10, 2011

Re: A Little Transom modifing

View attachment 112876Here is a picture of the inside of the boat

produceguy · Sep 10, 2011

Re: A Little Transom modifing

Attachment doesn't work.

Yacht Dr. · Sep 10, 2011

Re: A Little Transom modifing

This is not a difficult project

.. a 2 on a scale of 5.

1. Remove the SS rails on the deck cap.
2. Use 1" masking tape to make your cut lines.
3. Your hinge cut will be in line ( straight cut ) .. your swing side will be slightly larger on the inside and smaller on the outside ( about 2" would be good ).
4. Fiberglass a strip of wood on the underside of your cutout area extending about 1' each end of the cut-out location.
5. Cut your trans/door ( ON YOUR LINES ).
6. Tape some formica on both sides of your transom cuts ( finished side beam to beam ).
7. Brush gelcoat and then glass the sides of your trans cutouts ( glass a strip of wood where your hinge will be ).
8. Do the same steps on your cutout door but in reverse ( mold formica on the outside of the door cutout and glass and wood strip the inside ends ).
9. If your going to have an inside face on the door then glass some strips of wood on the inner edges of the door.
10. Drill and install with piano hinge or dual SS hinges.

Its harder to describe how to then to actually do it lol

.. PM me if want my # and I will talk you through the basic steps.

Take Pics !!

..

YD.

relocyo · Sep 10, 2011

Re: A Little Transom modifing

This looks like a neat project, please keep us updated on this one!

produceguy · Sep 10, 2011

Re: A Little Transom modifing

Yacht Dr. said:
This is not a difficult project .. a 2 on a scale of 5.

1. Remove the SS rails on the deck cap.
2. Use 1" masking tape to make your cut lines.
3. Your hinge cut will be in line ( straight cut ) .. your swing side will be slightly larger on the inside and smaller on the outside ( about 2" would be good ).
4. Fiberglass a strip of wood on the underside of your cutout area extending about 1' each end of the cut-out location.
5. Cut your trans/door ( ON YOUR LINES ).
6. Tape some formica on both sides of your transom cuts ( finished side beam to beam ).
7. Brush gelcoat and then glass the sides of your trans cutouts ( glass a strip of wood where your hinge will be ).
8. Do the same steps on your cutout door but in reverse ( mold formica on the outside of the door cutout and glass and wood strip the inside ends ).
9. If your going to have an inside face on the door then glass some strips of wood on the inner edges of the door.
10. Drill and install with piano hinge or dual SS hinges.

Its harder to describe how to then to actually do it lol .. PM me if want my # and I will talk you through the basic steps.

Take Pics !! ..

YD.

Yact Doc, I thought of that as well but what about the integrity of the transom. Couldn't this method jeperdise the strenght of it?
Maybe tab in the bottom of the frameing to the deck?

This is a neat project.

ondarvr · Sep 10, 2011

Re: A Little Transom modifing

Without a pic your boat an exact recommendation can't be made, but typically you need to beef up the area around and below the cutout to take the added stress.

Jamie 10017 · Sep 10, 2011

Re: A Little Transom modifing

The blue boat in the picture is my boat, Its the one I want to cut the transom and install the walk thru. Thanks to all for the input and ideas. Please feel free to add any thoughts or ideas Jamie

sqbtr · Sep 10, 2011

Re: A Little Transom modifing

The boat has a V drive, I doubt there is much structure in the transom. Grab the sawsall and have at it. The hardest part is going to be dealing with the railing and the rub rail.

Jamie 10017 · Sep 10, 2011

Re: A Little Transom modifing

You are correct the transom is hollow down to the deck, I will not be cutting anything below that point. The rub strip is getting replaced and the rail is already open where I want to cut.

ondarvr · Sep 10, 2011

Re: A Little Transom modifing

Even though it's a V drive there is still a great of stress placed on the transom and this portion helps to keep the boat from flexing and although the area to be removed is hollow, the height of it adds a great deal of stiffness to the entire structure. How much the design depends on this stiffness can't be know unless you have it evaluated by a composites engineer.

Now I don't expect you to have this done, that's why I suggest you beef up the area to help compensate for removing a large section.

Jamie 10017 · Sep 12, 2011

Re: A Little Transom modifing

What type wood should I use to box in the opening were I cut? How should I seal it so that I can glass over it and spray gel coat on it. I really want this to look good. Thanks, Jamie

JDA1975 · Sep 12, 2011

Re: A Little Transom modifing

If it is hollow couldn't you just "truss" both sides of the door, 1 vertical and one diagonal going from top of transom to the side would essentially transfer the weight lost by cutting it out. I am no structural engineer by any means but have built houses many times with open vaulted ceilings and used similar truss designs. on such a short span 1 upright plus a diagonal should suffice, Glass the wood straight to the existing transom before cutting so you have zero shift if it needed that structural integrity.

Yacht Dr. · Sep 13, 2011

Re: A Little Transom modifing

Yacht Dr. said:
This is not a difficult project .. a 2 on a scale of 5.

1. Remove the SS rails on the deck cap.
2. Use 1" masking tape to make your cut lines.
3. Your hinge cut will be in line ( straight cut ) .. your swing side will be slightly larger on the inside and smaller on the outside ( about 2" would be good ).
4. Fiberglass a strip of wood on the underside of your cutout area extending about 1' each end of the cut-out location.
5. Cut your trans/door ( ON YOUR LINES ).
6. Tape some formica on both sides of your transom cuts ( finished side beam to beam ).
7. Brush gelcoat and then glass the sides of your trans cutouts ( glass a strip of wood where your hinge will be ).
8. Do the same steps on your cutout door but in reverse ( mold formica on the outside of the door cutout and glass and wood strip the inside ends ).
9. If your going to have an inside face on the door then glass some strips of wood on the inner edges of the door.
10. Drill and install with piano hinge or dual SS hinges.

Its harder to describe how to then to actually do it lol .. PM me if want my # and I will talk you through the basic steps.

Take Pics !! ..

YD.

You should read this AGAIN .. this time very slowly until it sinks in

.. ( this quote is unedited and is a basic step by step to get you going.. should you need more info just post away ).

This method will Make you a frame and door thats already braced at the door. Of course your going to have finish work on the bottom side and other gel finishes.. But we are not at that point yet. Make the door and the finish is the final step

..

YD.

Jamie 10017 · Sep 13, 2011

Re: A Little Transom modifing

I'm just trying to make sure I have all this correct before I cut the rear of my boat off. I didn't know if glass sticks to formica or not. I dont know if gel coat will either and I don't know what to use to seal it all up. Thats why I ask maybe I'm a little sloooooooow+

A Little Transom modifing

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