Bombard C5 Seam question..

[Bodge]

I just took a look at a 80's (?) C5 that I could pick up for a song.

The Good.

Tubes look great and have no leaks or patches.

The aluminum floor is complete and in good shape.

The Bad.

The transom is coming unglued and half way off. I can pull the joints apart by hand.

The hull material has peeled back about 3' on both sides and can also be pulled apart by hand.

Although these are rather large issues, I would be willing to take it on if I knew the tube seems were welded and not glued. I worry about the tubes coming apart if they are indeed glued.

Does anyone know if the tubes are welded or glued? Should I just walk away from the boat?

Any info you can give me would be greatly appreciated.

[spartacus]

I suspect it's welded seams on the tubes (likely to be PVC or Strongan Duotex) and a glued transom. The transom repair is straight forward with the right preparation and ambient temperature.

The tubes can be repaired, again, depends on the extent of damage, and how strong existing weld still is. I know later Zodiacs moved the seam below the waterline, as they were previously located under the rowlocks and rope lace cuff. If this one has the seam above, then walk away, as nigh impossible to fix.

[Bodge]

Thanks for the reply spartacus.

I will have to look at the boat again to check the seam location.

The asking price is $250 Canadian dollars or 136 Pounds. At that price I would be willing to throw some time and money at it if I was reasonably sure about the seams holding up.

[jwalker]

Originally Posted by Bodge

Thanks for the reply spartacus.

I will have to look at the boat again to check the seam location.

The asking price is $250 Canadian dollars or 136 Pounds. At that price I would be willing to throw some time and money at it if I was reasonably sure about the seams holding up.

I've replaced the whole hull fabric on a C5, it's pvc and using the correct method there is no problem. Many years ago I posted the gluing method on ribnet so a search should pick it up. My tubes where welded but the hull to tube joint was a glued joint. The vintage was early 1990's.

The transom is a slightly different issue because you're using pvc adhesive to glue onto the transome finish, not pvc, so you're kinda using an inappropriate adhesive for the task and eventually it is likely to fail. It's probable that if you start over by cleaning everything back to bare materials, you'll get it back to as strong a joint as it was when new.

For info, the reason for replacing the hull was to reshape it to make the boat more seaworthy. I increased the height of the keel wood, particularly towards the bow, and made the new hull to suit. It worked very well and much improved the ride in bumpy seas. If you're doing a full hull replacement, I recommend it. It doesn't need much increase in keel depth so it's not entirely radical.

[office888]

You will need to unglue and reglue the entire floor and the entire transom.

DO NOT JUST PULL IT OFF. Use some heat. You may damage the PVC coating otherwise.

The transom wood needs a special primer.

The tubes are ~99% welded. There are some glued penetrations where the baffles were installed. Typically, the penetrations were hidden under the lacing cuff or the floor joint.

[Bodge]

Originally Posted by jwalker

I've replaced the whole hull fabric on a C5, it's pvc and using the correct method there is no problem. Many years ago I posted the gluing method on ribnet so a search should pick it up. My tubes where welded but the hull to tube joint was a glued joint. The vintage was early 1990's.

The transom is a slightly different issue because you're using pvc adhesive to glue onto the transome finish, not pvc, so you're kinda using an inappropriate adhesive for the task and eventually it is likely to fail. It's probable that if you start over by cleaning everything back to bare materials, you'll get it back to as strong a joint as it was when new.

For info, the reason for replacing the hull was to reshape it to make the boat more seaworthy. I increased the height of the keel wood, particularly towards the bow, and made the new hull to suit. It worked very well and much improved the ride in bumpy seas. If you're doing a full hull replacement, I recommend it. It doesn't need much increase in keel depth so it's not entirely radical.

I was prepared to walk away from the boat but now I'm giving it second thoughts. I do have some DIY gluing experience behind me and am confident I could do a reasonable job with the right preparations and products at hand.

The keel modification you mentioned sound very interesting and I will track down your thread and give it a read.

Thanks for your reply.

[Bodge]

Originally Posted by office888

You will need to unglue and reglue the entire floor and the entire transom.

DO NOT JUST PULL IT OFF. Use some heat. You may damage the PVC coating otherwise.

The transom wood needs a special primer.

The tubes are ~99% welded. There are some glued penetrations where the baffles were installed. Typically, the penetrations were hidden under the lacing cuff or the floor joint.

Thanks for the reply.

The transom wood is in good shape and would not take much too sand down to fresh wood. But I am not sure what product to seal the wood with after sanding. I take it that paint is not a good idea?

Also, the primer needed, do I apply that directly to the wood, build up a layer and then use the appropriate PVC glue?

[jwalker]

Originally Posted by Bodge

The transom wood is in good shape and would not take much too sand down to fresh wood. But I am not sure what product to seal the wood with after sanding. I take it that paint is not a good idea?

Any good quality epoxy marine paint is likely to be ok. Polyester (fibreglass) resin would be ok too. You'd need to add a wee drop of wax to it to prevent it remaining sticky on the surface.

[Bodge]

Originally Posted by jwalker

Any good quality epoxy marine paint is likely to be ok. Polyester (fibreglass) resin would be ok too. You'd need to add a wee drop of wax to it to prevent it remaining sticky on the surface.

Thanks for the advice. If I've taken the whole thing apart I might as well give the transom a thin layer of glass cloth and be done with it, paint then reassemble.

[jwalker]

Originally Posted by Bodge

Thanks for the advice. If I've taken the whole thing apart I might as well give the transom a thin layer of glass cloth and be done with it, paint then reassemble.

If you do that, be sure to rough up the surface of the wood to provide a key - drag a hand saw criss-cross all over it to tear it up - because polyester resin doesn't adhere well to the surface of plywood.

[Bodge]

Originally Posted by jwalker

If you do that, be sure to rough up the surface of the wood to provide a key - drag a hand saw criss-cross all over it to tear it up - because polyester resin doesn't adhere well to the surface of plywood.

Good point, I'll prep as you say.

[Bodge]

A deal has been struck.

Boat is free and I get the 5 year old galvanized trailer for $300. or 165 pounds. Pick up is tomorrow morning.

I'm quite chuffed!!

[Bodge]

Picked up the boat this morning and was very surprised to learn that the trailer was offered to me for free. Its a solid bit of galvanized kit and totally road worthy. Felt bad about taking it for free so I threw in some more money for a posh dinner in appreciation. I couldn't be happier with the way things went.

[Bodge]

More pictures

[office888]

A warning for you my friend:

The boat is a 1985. Looking at the seams, this is"hybrid" year. Zodiac experimented with cross gluing PVC-to-CSM and vice versa.

Hypalon/CSM tubes
PVC d-rings
PVC transom attachment
PVC floor
PVC keel (maybe?)
PVC baffles (maybe?)

The good news is that if you reglue the transom with CSM/Neo material instead of PVC, the gluing will last an indefinite amount of time. If you reglue with PVC, you'll probably get another 10-15 years before regluing is required.

[Bodge]

Originally Posted by office888

A warning for you my friend:

The boat is a 1985. Looking at the seams, this is"hybrid" year. Zodiac experimented with cross gluing PVC-to-CSM and vice versa.

Hypalon/CSM tubes
PVC d-rings
PVC transom attachment
PVC floor
PVC keel (maybe?)
PVC baffles (maybe?)

The good news is that if you reglue the transom with CSM/Neo material instead of PVC, the gluing will last an indefinite amount of time. If you reglue with PVC, you'll probably get another 10-15 years before regluing is required.

Thanks for the heads up.

So if I understand this correctly, I would be better off replacing all the transom support bits with hypalon material and glue. Would I need any kind of primer coat applied first or just use standard hypalon gluing methodology...

[office888]

Originally Posted by Bodge

Thanks for the heads up.

So if I understand this correctly, I would be better off replacing all the transom support bits with hypalon material and glue. Would I need any kind of primer coat applied first or just use standard hypalon gluing methodology...

Standard hypalon glue layup. It bonds just fine to wood with no special primer.

You may have a piece of "rubber" triangular extrusion underneath the strip that goes from the transom to the boat. That is made of a PVC material and will need to be replaced by a piece of EPDM or Neoprene.

You could probably use the piece from the F470. Zodiac PN Z7015 "Transom Extrusion , NEO (2m).

[Bodge]

Originally Posted by office888

Standard hypalon glue layup. It bonds just fine to wood with no special primer.

You may have a piece of "rubber" triangular extrusion underneath the strip that goes from the transom to the boat. That is made of a PVC material and will need to be replaced by a piece of EPDM or Neoprene.

You could probably use the piece from the F470. Zodiac PN Z7015 "Transom Extrusion , NEO (2m).

Thanks for the great info and the part number.

The "rubber" piece on my GR MK2 is quite noticeable, the one on the C5 is almost nonexistent. I have not disassembled anything yet as I am away working and need to drag the boat home when done here. Is it possible that the C5 may not have one?

[office888]

Originally Posted by Bodge

Thanks for the great info and the part number.

The "rubber" piece on my GR MK2 is quite noticeable, the one on the C5 is almost nonexistent. I have not disassembled anything yet as I am away working and need to drag the boat home when done here. Is it possible that the C5 may not have one?

The engineer behind the boat may have decided to omit it as a cost savings to keep the product price lower.

If you are using the boat with a moderate size older 2-stroke, you probably have nothing to fear.

The piece serves to reduce the forces on the transom-to-tube material connection. By reducing the angle to a slow progression, it maximizes the the gluing strength so the glue is only tensioned at its "strongest" positions. Glue is weak from a "peeling" motion, but is strongest when present with forces that pull directly "upward" from the base substrate.

By having a sharp angle, there is a possibility of it peeling from the center then outward.

Of course, by upgrading to CSM/Neo fabric, you may eliminate this possibility.

If there is no "rubber" piece, I would simply use some heavy duty black fabric. You should be able to source from black Pennel & Flipo Orca 866 or similar? It has a heavier polyester base fabric to it.

When you are templating the old cuts, I would extend them outwards an additional 1-2" or so...more gluing overlap can only help. Also, be sure to pay attention to the crosshatching bias of the fabric (if you look close, you can see a "#" shaped weave). It stretches easier with an angle against the "grain" of the weave. If you try to stretch against the weave, it will not stretch.

[Squid Boat]

Great to see this fine boat coming back into service.

I would like to say thanks to Richard (Office888) for his knowledgeable posts
to this community. He has also been a big help to me.

Cheers,