I'm looking for information on the construction of the GH31 rudder blade, which I assume was standard for all 'kit built' boats.
I have a problem in that a crack has appeared running from the top near the stock across towards the trailing edge and is almost the same on each side.
The rudder appears to be made up of a plank running from the tiller head to the foot with added pieces at the top to make up the stock. Outside that first plank are two more planks making up the rudder blade. I think the planks are fastened together with bolts running through them as there are three or so plugs/filler showing on the leading edge. Can someone confirm this? Would they be stainless steel?
I had sheathed the blade before last season but this has now cracked on one side so the blade is clearly flexing. If the fastenings are known to be heavy enough then I would just try routing out the crack, filling with epoxy and then some heavier cloth. However if there is any suggestion due to the nature of the fastenings that they have failed then a more lasting solution will have to be applied as it is my son's intention to take the boat to the Med in 2016.
Very grateful for any information or advice on the matter.
Golden Hind 31 rudder blade.
Moderators: Eventide Owners Group, Piskie, chris s
Re: Golden Hind 31 rudder blade.
Hello there i have plans details of the rudder construction from Terry Erskine if you would like them email me and i will fax them to you hope that helps any other details i can help you with,regards Dave.
Re: Golden Hind 31 rudder blade.
Hi.
Terry Erskine made the blades up from Iroko boards. There was a single full length board forming the centre of the stock and the front section of the blade. This was cut from the widest board they had available so as to include as much of the blade as possible and avoid having a butt joint right in the radius at the top of the blade where it went into the stock. i.e The board was cut away for the stock and included the radius at the top of the blade. It was then butt jointed to two (usually) others to form the rest of the blade. Three half inch (I think) galvanised tie rods were then fitted through the blade fore and aft to pull all the sections together on resourcinol glue, so you should find three large wood plugs on the forward and aft edges, covering the galvanised nuts.
I don't know whether you feel you need to remove them (I would be surprised), but if you do you may find them corroded. You will have to drive them out one side or the other and I would replace them with A4 stainless studding.
The stock was finished with a further board glued and screwed together, on each side of the stock, to make up the full thickness. These stopped right at the top of the blade/waterline, which I always felt was the weak point and may well explain some movement affecting the sheathing. When I made rudders up in wood before I changed to GRP, I extended the cheek boards below the waterline by about a foot to better support the blade, and gently faired them away into the blade in a smoth profile, as well as on the leading edge. At the time I'm fairly sure the boards were screwed with brass screws which may have suffered if water got behind the sheathing.
You don't say much about how you sheathed the blade or what was the state of the original sheathing, assuming it was. I think I would strip the old sheathing very well back from the area, and anywhere is has detached or water has got behind. That was quite common because of the large area, high loading and flexure. Make sure it has all very thoroughly dried out and re-sheath with a decent weight woven cloth
Hope this may help.
Mark
Terry Erskine made the blades up from Iroko boards. There was a single full length board forming the centre of the stock and the front section of the blade. This was cut from the widest board they had available so as to include as much of the blade as possible and avoid having a butt joint right in the radius at the top of the blade where it went into the stock. i.e The board was cut away for the stock and included the radius at the top of the blade. It was then butt jointed to two (usually) others to form the rest of the blade. Three half inch (I think) galvanised tie rods were then fitted through the blade fore and aft to pull all the sections together on resourcinol glue, so you should find three large wood plugs on the forward and aft edges, covering the galvanised nuts.
I don't know whether you feel you need to remove them (I would be surprised), but if you do you may find them corroded. You will have to drive them out one side or the other and I would replace them with A4 stainless studding.
The stock was finished with a further board glued and screwed together, on each side of the stock, to make up the full thickness. These stopped right at the top of the blade/waterline, which I always felt was the weak point and may well explain some movement affecting the sheathing. When I made rudders up in wood before I changed to GRP, I extended the cheek boards below the waterline by about a foot to better support the blade, and gently faired them away into the blade in a smoth profile, as well as on the leading edge. At the time I'm fairly sure the boards were screwed with brass screws which may have suffered if water got behind the sheathing.
You don't say much about how you sheathed the blade or what was the state of the original sheathing, assuming it was. I think I would strip the old sheathing very well back from the area, and anywhere is has detached or water has got behind. That was quite common because of the large area, high loading and flexure. Make sure it has all very thoroughly dried out and re-sheath with a decent weight woven cloth
Hope this may help.
Mark
Re: Golden Hind 31 rudder blade.
Many thanks Mark.
Your description confirms my thoughts on the rudder construction. Unfortunately I'm not certain at the moment which direction the crack goes as I'm in Cardiff and the boat is in the yard at Parkstone. The crack was diagonally across the grain but with the clearly visible planks still firmly together.
The rudder wasn't originally sheathed and I took it down to the bare wood before epoxy sheathing it. I can't remember the cloth weight but clearly not heavy enough although oddly enough it has only opened up on one side. I noticed the three plugs/filler when I stripped the blade and there was no sign of any movement there.
When the boat came out last autumn I did a temporary epoxy fill to prevent winter seepage but water probably got in before so it will need a bit of exploring to see how much has detached. I'll then strip back, dry out and re-epoxy sheath with heavier cloth.
I'm not tempted to remove the tie rods quite yet but if at the end of the season the crack has manifested itself again I'll bring the rudder home and see what needs to be done. If we take her to the Med next year I won't want to take any chances.
Again, many thanks for your help. As you will have guessed I'm a member of Parkstone YC where you re-masted David's Sea Wyf. I seem to remember contacting you before but the reason escapes me.
Regards.
Hywel.
Your description confirms my thoughts on the rudder construction. Unfortunately I'm not certain at the moment which direction the crack goes as I'm in Cardiff and the boat is in the yard at Parkstone. The crack was diagonally across the grain but with the clearly visible planks still firmly together.
The rudder wasn't originally sheathed and I took it down to the bare wood before epoxy sheathing it. I can't remember the cloth weight but clearly not heavy enough although oddly enough it has only opened up on one side. I noticed the three plugs/filler when I stripped the blade and there was no sign of any movement there.
When the boat came out last autumn I did a temporary epoxy fill to prevent winter seepage but water probably got in before so it will need a bit of exploring to see how much has detached. I'll then strip back, dry out and re-epoxy sheath with heavier cloth.
I'm not tempted to remove the tie rods quite yet but if at the end of the season the crack has manifested itself again I'll bring the rudder home and see what needs to be done. If we take her to the Med next year I won't want to take any chances.
Again, many thanks for your help. As you will have guessed I'm a member of Parkstone YC where you re-masted David's Sea Wyf. I seem to remember contacting you before but the reason escapes me.
Regards.
Hywel.