|
|
23-01-2022, 12:03
|
#1
|
Registered User
Join Date: Jul 2021
Location: Toronto, Canada
Boat: Alberg 37 MKII 1975
Posts: 54
|
Alberg 37 MKII 1975, building new rudder
Hi there,
Need some advise on building new rudder for Albert 37, MKII, 1975.
After reading some blogs and watching youtube videos I have made core out of Douglas Fir.
I am planning to cover it with at least four layers of fiberglass with epoxy resin.
I am thinking to put is as follows: stranded mat/woven rowing/stranded mat/biaxial cloth with mat.
This choice is based on leftover I have from other projects.
Before I go ahead and do it my concerns are:
1. Is it safe enough to have wood as a core as some say that of water gets in the core the rudder will crack. I am planning to glass over all the would tough and leave no spots there stock or any other material will touch the wood. If wood core is not a good idea them second options is to use the core that I made as a mold to make two shells and glass then together and fill in the foal inside.
2. Any idea how the best to center/align the rudder stock with bronze stock which is connect to the gudgeon and small round of bronze which sits on the rudder shoe
3. I have inspected the rudder stock and there is a very tiny worn out where stock was touching the packing nut. I keep my fingers on it on the picture.
4. The fist board on the pick has tiny surface cracks, they are not deep and really small as you can see. Should I just glass it over or have it cut of and replaced with new board without cracks. I am not concerned about structural integrity of wood, but more concerned about leaving tiny voids under the glass. Could it be a problem in the long run or I am just too paranoid.
Any other practical advises of the building new rudder will be greatly appreciated as this is my first boat, first everything. Got the boat back in June 2021 and hoping to splash it at the end of May.
Thank you in advance.
|
|
|
23-01-2022, 13:54
|
#2
|
Registered User
Join Date: Dec 2008
Location: Noank, Ct. USA
Boat: Cape Dory 31
Posts: 3,170
|
Re: Alberg 37 MKII 1975, building new rudder
I’ve seen many rudders over the years with water intrusion issues. If I were to undertake the task I would avoid wood and go with foam. It’s easier to deal with some wet foam and the remedial actions necessary than it is to deal with a rotten core which would necessitate a full removal and replacement to retain rigidity. Water migrates through wood, hence the large number of deck core removal and replacement guides and videos.
|
|
|
23-01-2022, 15:09
|
#3
|
Registered User
Join Date: Jul 2021
Location: Toronto, Canada
Boat: Alberg 37 MKII 1975
Posts: 54
|
Re: Alberg 37 MKII 1975, building new rudder
Thank you Jim, I will think about it. It's just easier for me to work with wood then making molds and so on. But i agree with you on the water intrusion and rotting wood on the long run.
|
|
|
23-01-2022, 16:03
|
#4
|
Registered User
Join Date: Oct 2019
Location: Kennebunk ME
Boat: Owner built 60’ Aluminum Expedition Yacht.
Posts: 1,854
|
Re: Alberg 37 MKII 1975, building new rudder
The manatee crew feels you are doing a fine job.
|
|
|
23-01-2022, 16:50
|
#5
|
Marine Service Provider
Join Date: Dec 2010
Location: Little Compton, RI
Boat: Cape George 31
Posts: 2,978
|
Re: Alberg 37 MKII 1975, building new rudder
I'd use Coosa board and treat it exactly as though it were wood, and then never worry about it again. Coosa's expensive, but you'll only do it once. Maybe a thicker laminate schedule--you want about a 1/4" of layup on each side, but you could use Vinylester, which is cheaper than epoxy. It would only take two or three more layers each side. You can caliper the glass stack when it's dry to see how thick it will end up.
__________________
Ben
zartmancruising.com
|
|
|
23-01-2022, 17:04
|
#6
|
Registered User
Join Date: Jul 2021
Location: Toronto, Canada
Boat: Alberg 37 MKII 1975
Posts: 54
|
Re: Alberg 37 MKII 1975, building new rudder
Thank you manatee crew for your word of encouragement.
|
|
|
23-01-2022, 17:38
|
#7
|
Registered User
Join Date: Jul 2021
Location: Toronto, Canada
Boat: Alberg 37 MKII 1975
Posts: 54
|
Re: Alberg 37 MKII 1975, building new rudder
Thank you Ben. Will check Vinylester option.
|
|
|
23-01-2022, 17:57
|
#8
|
Registered User
Join Date: Nov 2006
Location: Back in Northern California working on the Ranch
Boat: Pearson 365 Sloop and 9' Fatty Knees.
Posts: 10,466
|
Re: Alberg 37 MKII 1975, building new rudder
I probably would not use wood as the slightest intrusion of water would start a problem. I think Urethane foam or the aforementioned Coosa board would be the way to go.
Is that the actual size of the rudder shaft? It looks small.
__________________
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well-preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming: Wow - what a ride!"
|
|
|
23-01-2022, 18:34
|
#9
|
Registered User
Join Date: Jul 2021
Location: Toronto, Canada
Boat: Alberg 37 MKII 1975
Posts: 54
|
Re: Alberg 37 MKII 1975, building new rudder
Yes, the shaft is 1 1/4 inch in diameter.
Total length of the rudder with shaft from shou to tiller head is flimsy 10 feet long.
|
|
|
23-01-2022, 21:33
|
#10
|
Registered User
Join Date: Aug 2021
Location: PNW
Boat: 35 Ft. cutter, custom
Posts: 2,251
|
Re: Alberg 37 MKII 1975, building new rudder
Rudders built with fiberglass-over-foam or using injected foam into a "clamshell" of molded fiberglass generally have several straps welded to the stock that extend into the foam a fair distance to prevent the shaft from simply turning inside the rudder.
As per the pictures, the anchor point of the OPs rudder shaft is only "fastened" as it were, to a small area in one section at the top.
This means that the core/shell of the rudder must be stiff enough to transmit all the torque applied to the shaft connection area down to the lower area that has no actual connection to the shaft.
A very heavy laminate schedule can do that, but it will be quite heavy.
A wood core can transfer the torque, but it must be kept dry.
Keeping a wood core dry is not a big deal in and of itself, the problem is keeping water out of the joints where the metal parts penetrate the fiberglass to connect to the wood.
It's kind of a job that's "Between the Devil and the Deep Blue Sea".
The original rudder has lasted over 45 years, the builders must have done something right, right? How did they do it?
Given the decision, I might well choose to build a Teak rudder without glass, but that requires some semi-advanced skills with edge fastening, and even though expensive, glass and epoxy isn't exactly cheap either.
The OPs plan can work, and with some careful attention to detail(s) their isn't any reason his new rudder couldn't give good service for many years.
I would however literally soak the wood in Smiths CPES for a good long period, before glassing it.
As other posters have noted, synthetic materials can be used instead of wood but care must be made to prevent crushing the core where fasteners/bolts are used.
If foam is desired, I would use a high-density stuff, up in the 30>40lb range.
|
|
|
23-01-2022, 22:56
|
#11
|
Registered User
Join Date: Jul 2012
Location: North East USA
Boat: 1975 Tartan 41'
Posts: 1,044
|
Re: Alberg 37 MKII 1975, building new rudder
chop strand mat is not compatible with epoxy. Don't use it! Chop strand mat uses a binder that is soluble in Styrene, for use with polyester resin, not epoxy. The biax layered with stitched mat should be fine as it is stitched together. But personally, I'd just use one type of woven fabric for the whole job. You can rotate it 45 degress to get strength on the bias without buying a separate type of glass if you want (probably not needed). buying 1 type of cloth reduces waist in cut-offs and allows you to get bulk discount at purchase. As far as layers, that depends on the weight of each fabric. In short, just match the thickness of glass that was on the original rudder. You could use a few dozen layers of 6oz or maybe just a few 20oz layers. It really doesn't matter as long as you get the proper build up of thickness.
As for your cracks. Before you fiberglass wood, you always need to coat it with resin first. This prevents a dry layup from the wood absorbing resin, but should also fill any small cracks in your wood. Don't worry about that.
You will get water in the rudder eventually due to different thermal expansion of the metal, plastic and wood. water will get down the rudder shaft eventually. The wood will rot, eventually. 5, 10, 20 years..?? who knows
|
|
|
24-01-2022, 07:04
|
#12
|
Registered User
Join Date: Jul 2021
Location: Toronto, Canada
Boat: Alberg 37 MKII 1975
Posts: 54
|
Re: Alberg 37 MKII 1975, building new rudder
Thank you Bowdrie and Zstine for your advices.
Decision made. I will go with heavy glassing over the blank that I have made and i might start building second rudder later on if I have time and energy.
Thank you all for your input.
Much appreciated.
|
|
|
24-01-2022, 08:43
|
#13
|
Registered User
Join Date: Feb 2020
Location: Lymington UK
Boat: UFO27 Holman & Pye 8.2m
Posts: 259
|
Re: Alberg 37 MKII 1975, building new rudder
Chop stran mat for epoxy
https://www.ecfibreglasssupplies.co....tting-1mt-wide
I would assume this is available in the USA
John
|
|
|
24-01-2022, 11:46
|
#14
|
Registered User
Join Date: Jul 2021
Location: Toronto, Canada
Boat: Alberg 37 MKII 1975
Posts: 54
|
Re: Alberg 37 MKII 1975, building new rudder
Yes, it is
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|
|