Hull deck joint ....

[markle]

Hi everyone, I have recently resurrected my pilgrim 25 project, had her lifted into a yard and have started in earnest!

Some random pics of the project before she stalled - bought a rigid raider and spent some time on that - here (it is now a full rebuild - cabin all done just a few jobs left before a sand and paint)

http://www.ybw.com/forums/album.php?albumid=896

I am a little stuck on the hull deck join. Originally she had wooden strake, bolted top and bottom and then a covering piece over the top screwed to both halves.

I assume this was to assist in keeping hull and deck together!

now there is no strake at all, it is in many pieces in the tip!

The join is like this:



Apologies for the child like drawing - best I could muster on paint!

So it has an outward flange riveted, and reasonable heavily glassed up on the inside - i would guess 3 layers of 600g/m chopped (although when it was layed up metric was a long way away!).

There are sectioned of the flange that have snapped or been worn away.

Is it feasible to just grind the whole flange off ..... and layer up 3 or 4 layers of glass over the top? I can run it up a good inch either side (deck and hull) giving 2-3 inches of contact point!

This will alleviate the issue of planing lots of iroko to fit the profile of the hull/deck as if i get rid of the flange i could bolt a decent rubber fender top and bottom.

Any advice welcome and appreciated

glad to be back on the project finally!

Mark

 

[Tranona]

Don't grind it off. The flange is the joint. The lamination inside is reinforcement and to tidy the joint up. Alternative to a wood strake is a flexible gunwhale fendering which you can get in different profiles to fit over the flange and locate on the bolt heads. Good selection from Wilkes Rubber.

 

[markle]

Thank you for the reply - main reason for the grinding proposal is that several areas of the flange are now too damaged to rivet - and a massive pain to build back out in glass. Many of the rivets are also now gone! Some sections are ok some not.

Interim plan is to glass up the sections that can not be bolted or riveted back together and bolt the rest.

If I did grind I would lay up heavily with woven matt on the outside - I was thinking just make the hull and deck one piece! I do not plan on ever taking it apart

Is there a solution to the tiny remaining flange (in places) as that is the real problem.

I feel the strake was doing a better job than the flange for parts of the join at holding things together! May just glass what I cant bolt and bolt the rest. Still like the idea of a nice smooth joint tho ....

 

[markle]

here is another childs drawing from above showing the type of problem I am struggling to describe!

Some good flange some bad flange = whatever the problem I think the damage was done years ago but lucky me, it has fallen to me to find a remedy!

 

[PuffTheMagicDragon]

I can't see any problems with grinding off the flange in sections, leaving riveted sections in between. Apply tabbing to hold the deck and hull in alignment. Grind off the remaining (riveted) sections and complete the tabbing. Build up the complete 'belt' all round the hull with more GRP as necessary. In effect you will have made a new, stronger, sheer strake in GRP. Fair and apply whatever rubbing strip you prefer. Personally I prefer a wooden one and would not use rubber

 

[30boat]

I can't see any problems with grinding off the flange in sections, leaving riveted sections in between. Apply tabbing to hold the deck and hull in alignment. Grind off the remaining (riveted) sections and complete the tabbing. Build up the complete 'belt' all round the hull with more GRP as necessary. In effect you will have made a new, stronger, sheer strake in GRP. Fair and apply whatever rubbing strip you prefer. Personally I prefer a wooden one and would not use rubber

Agree entirely.Make sure the grp surface is well abraded and if at all possible use epoxy.You'll get a strong joint.

 

[William_H]

I tend to feel that you should not grind off the flange where it remains. The hull to deck juoint is pretty important particularly if you suffer a collision or similar pressure on the side of the hull. having said that I would not worry so much about the areas where the flange has dissapeared. I would go for wood or rubber as a cover for the flange.
I think if you cut off all the falange and tried to fair in a patch belt over the join you will find it a lot of work to get a decent looking finish. Indeed you might still end up fitting a rubbing strake over the grp belt. Just to hide it. good luck olewill

PS you might think a collision unlikely. My little boat has had many sideways bangs from collisions to bashing against a jetty. GRP is incredibly tough and never had much damage just cosmetic but I am sure if the joint was compromised it would open up under side pressure.