As for the glass fiber I have got chopped strand for sandwiching the ply core however when it comes to marrying the roof lid to the cabin roof I am unsure whether to use the same chop strand or use woven. Any ideas on that?
Craig.
Delaminated Cabin Roof - Shetland 535
Re: Delaminated Cabin Roof - Shetland 535
Hi Paul, yes I have already read your thread, great job too. I will be using epoxy resin with this, got a west system 5l kit, although I think I may need more. Can you remember roughly how much resin you used? My idea for shaping the ply was once the shape was cut for the hole I was going to take the circular saw and cut halfway into the ply in strips on the backside, this will allow it to mould into the camber shape. I would then add thickened epoxy into these grooves prior to glueing it down. I felt this was potentially the best way over using the strips as Id use less epoxy and also there would be more strength in the roof. Uneducated guess there
As for the glass fiber I have got chopped strand for sandwiching the ply core however when it comes to marrying the roof lid to the cabin roof I am unsure whether to use the same chop strand or use woven. Any ideas on that?
Craig.
As for the glass fiber I have got chopped strand for sandwiching the ply core however when it comes to marrying the roof lid to the cabin roof I am unsure whether to use the same chop strand or use woven. Any ideas on that?
Craig.
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paulturner64
- Posts: 47
- Joined: Thu Aug 31, 2017 6:26 pm
Re: Delaminated Cabin Roof - Shetland 535
Sorry Craig
I´ve been away and didn`t get to see your post until today.
The critical part of marrying new laminations to old is the area of contact between the two. For example joining two sections of flat sheet edge to edge should be a scarf joint, not a butt joint. Ideally the area of the scarf should be about twelve times the thickness of the laminate. CSM or woven rovings will both work, but be sure the laminations are well (but not over) wetted out and well rolled to remove bubbles.
After rolling the glass should become almost transparent within the lay up.
Hope it´s going well.
Paul
I´ve been away and didn`t get to see your post until today.
The critical part of marrying new laminations to old is the area of contact between the two. For example joining two sections of flat sheet edge to edge should be a scarf joint, not a butt joint. Ideally the area of the scarf should be about twelve times the thickness of the laminate. CSM or woven rovings will both work, but be sure the laminations are well (but not over) wetted out and well rolled to remove bubbles.
After rolling the glass should become almost transparent within the lay up.
Hope it´s going well.
Paul
Re: Delaminated Cabin Roof - Shetland 535
Hi Paul thanks for you reply. You say. Scarf joint. I assume you mean that the two sides will have to be ground down and the glass laminate layer inside the dip so to speak? As for progress, I am waiting on the weather to clear up, a miracle would suffice!
Craig
Craig
Re: Delaminated Cabin Roof - Shetland 535
Managed to get a start on the roof today, weather was fair so went for it. I cut my 9mm marine ply into strips and dry fit them. It was a tight squeeze sliding them under top skin but all went well. They conformed well the to the camber of the roof.
https://www.flickr.com/photos/134684491 ... ateposted/
https://www.flickr.com/photos/134684491 ... ateposted/
Before i took the wood back out I made sure to number them in sequence.. Then epoxy time had arrived.. I have to say I have been rather nervous about this part of the job, I have never used epoxy resin before let alone fiberglass work. My Michelle and I got stuck in once the chop strand was all cut.. Im glad she was there as she continued to wet the glass out as I mixed more resin.. Turns out shes much better at it than me!
We probably made a few mistakes doing this but we did make sure the resin was well mixed so it will harden off ok.. i hope
https://www.flickr.com/photos/134684491 ... otostream/
I had planned at this point to add the wood while it was all wet but since the wood needed a little persuasion to get into place I thought maybe when the glass has set it would be easier, just a lill more prep is needed but thats ok i guess. With the epoxy we had left we coated the edges of the wood ready for the next step.
In hindsight I should have really cut away more of the top skin.
https://www.flickr.com/photos/134684491 ... ateposted/
https://www.flickr.com/photos/134684491 ... ateposted/
Before i took the wood back out I made sure to number them in sequence.. Then epoxy time had arrived.. I have to say I have been rather nervous about this part of the job, I have never used epoxy resin before let alone fiberglass work. My Michelle and I got stuck in once the chop strand was all cut.. Im glad she was there as she continued to wet the glass out as I mixed more resin.. Turns out shes much better at it than me!
We probably made a few mistakes doing this but we did make sure the resin was well mixed so it will harden off ok.. i hope
https://www.flickr.com/photos/134684491 ... otostream/
I had planned at this point to add the wood while it was all wet but since the wood needed a little persuasion to get into place I thought maybe when the glass has set it would be easier, just a lill more prep is needed but thats ok i guess. With the epoxy we had left we coated the edges of the wood ready for the next step.
In hindsight I should have really cut away more of the top skin.
Re: Delaminated Cabin Roof - Shetland 535
Its beena wee while since i last posted on this thread. Progress has been made on the roof. The project went quite smoothly despite my partner and I being novices. I would really recommend anyone that is willing to give it a go to do so if your roof is as rotten as ours was.
So if your cabin roof looks like this, rotten to the preverbal core, you can fix it! Stewed steak anyone!
We gave the inside a good clean out and once dried we cleaned further with acetone and layed chopped strand fiberglass. I cant remember the weight of fiberglass we used but it was rather thick. Doing this stiffened the roof alot. You will notice the wood poking out of the hatch, I made these t bars that were roughly shaped to the curve of the roof. this helped keep the roof from sagging and kept the shape while work progressed.
Next we cut strips of 9mm marine ply and inserted into the hole we created and then mixed up some thickened epoxy and spread it between the ply and over the ply.. just generally anywhere where there was a gap. Then gave it a good sand.
Next phase was to reglue the lid with even more thickened epoxy. Prior to this I donned the paper suite and face mask and used a grinder with flap disk to create a channel on the lid and existing roof for fiberglassing. This was a messy job! There was a small gap between the lid and roof, the width of the cutting disk i used to initially cut it, So filled this gap with more thickened epoxy.
All glassed in as the pros say! next job we faired it with some west system 407, this was another messy job sanding but no itch this time and was a pleasure to see our hard work paying off.
This was as far as we got in 2023 The boat was harped over and we then decided to buy a Fiat ducato and convert it to a camper. Fast forward to this summer as we are back into boat mode...
Roof was done and after a few snagging jobs around the boat we were ready to strip most of the boat down for paint.
Ill post these pics tomorrow.
So if your cabin roof looks like this, rotten to the preverbal core, you can fix it! Stewed steak anyone!
We gave the inside a good clean out and once dried we cleaned further with acetone and layed chopped strand fiberglass. I cant remember the weight of fiberglass we used but it was rather thick. Doing this stiffened the roof alot. You will notice the wood poking out of the hatch, I made these t bars that were roughly shaped to the curve of the roof. this helped keep the roof from sagging and kept the shape while work progressed.
Next we cut strips of 9mm marine ply and inserted into the hole we created and then mixed up some thickened epoxy and spread it between the ply and over the ply.. just generally anywhere where there was a gap. Then gave it a good sand.Next phase was to reglue the lid with even more thickened epoxy. Prior to this I donned the paper suite and face mask and used a grinder with flap disk to create a channel on the lid and existing roof for fiberglassing. This was a messy job! There was a small gap between the lid and roof, the width of the cutting disk i used to initially cut it, So filled this gap with more thickened epoxy.
All glassed in as the pros say! next job we faired it with some west system 407, this was another messy job sanding but no itch this time and was a pleasure to see our hard work paying off.
This was as far as we got in 2023 The boat was harped over and we then decided to buy a Fiat ducato and convert it to a camper. Fast forward to this summer as we are back into boat mode...
Roof was done and after a few snagging jobs around the boat we were ready to strip most of the boat down for paint.
Ill post these pics tomorrow.
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Re: Delaminated Cabin Roof - Shetland 535
Next photo were probs on coat number 2. We made the fatal mistake with not thinning the paint. The resulting coats seemed patchy to say the least. We ended up with 3 coats last one using the thinners and it looked alot better, but not 100%.
That old soggy roof from last year has been fixed for sure and from what it looked like to today's looks its night and day!
In no way this was a professional job or looks like one, but from what we achieved with this project we are over the moon.
That old soggy roof from last year has been fixed for sure and from what it looked like to today's looks its night and day!
In no way this was a professional job or looks like one, but from what we achieved with this project we are over the moon.
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Re: Delaminated Cabin Roof - Shetland 535
Well done !!
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northernboy
- Posts: 10
- Joined: Sun Dec 17, 2023 11:29 am
Re: Delaminated Cabin Roof - Shetland 535
Well done - great job - I had the same issue on my Shetland 69 and tackled the job in the same way but from the inside.