Remove this ad

#21 [url]

May 3 12 8:46 AM

Unfortunately the boat is inside a tarp covered enclosure and I can't get enough distance on it to take those kind of shots.

Restoring a Bristol 29 in my backyard. www.bristol29.com

Quote    Reply   
Remove this ad
avatar

cadetrob

Able Bodied Seaman

Posts: 22

#22 [url]

May 3 12 7:13 PM

I see...well, actually, I don't. :-)  Look forward to seeing pics after you are done. It's impressive the attention to detail you put in. I might have to order that forward hatch you installed. Still waiting on rudder estimates.  Rob

Quote    Reply   
avatar

cadetrob

Able Bodied Seaman

Posts: 22

#23 [url]

Mar 25 13 8:18 PM



Hi David, I'm back  working on getting my B29 rudder repaired. I had this x-ray done today. The shot is taken of the starboard /top side of the rudder. To refresh your memory: The PO told me the rudder lifted off the shoe, the post bent and then the yard cut the rudder off the boat (see the bent stub in the x-ray shot). What do you think you would do from here? I have more (small area) x-ray shots of the rest of the rudder. The tech that took the shots is going to piece them together to give one full shot of the rudder. I was surprised to see that the post ended where it did. There is another (separate) post with 4 horizontal bars that leads from the gudgeon towards the prop opening. Btw,..... Where the rudder post ends at the top, is all the rudder post I have remaining....There is only a stub protruding from the top of the rudder. 











Quote    Reply   

#25 [url]

Mar 26 13 7:41 AM

How exciting to actually see into the rudder. I would not be concerned that the top part of the internal rudder post structure and the bottom structure are not connected. The rudder itself, being solid fiberglass is much too overbuild to torque or twist. What is of more importance is to see the long structural pins mounted to each end of the rudderpost that absolutely prevent any sort of slippage between the rudder and the stock.


For your situation, I think you could cut away the top few inches of the rudder to expose more of the top of the rudderpost, and have a new section welded to it. Then reform the area you cut away with epoxy and glass.


Cheers,


David

Restoring a Bristol 29 in my backyard. www.bristol29.com

Quote    Reply   
avatar

cadetrob

Able Bodied Seaman

Posts: 22

#26 [url]

Mar 26 13 8:14 PM

Hi David, That sounds like a great (and easier) solution but would you be concerned that welding more post to the existing post would not be strong enough to hold up under strong conditions? When I get the full rudder x-ray shot, I'll post it. 

Below is a link to pics of my rudder shoe and of the bottom of the rudder. What do you think of the rudder shoe and gudgeon? It looks like I need to rebuild those areas. I looked at your pics of your rudder on your restoration site and it looks like the bottom of your rudder and the top of your shoe sit flat/flush. Is that correct?  Also, I noticed that under the athwartship bolt, there is an opening to the ground.Is that part of the original design? As always, thanks for your help, Rob




http://s3.photobucket.com/user/cadetrob/library/B29%20Rudder?page=1

Quote    Reply   

#27 [url]

Mar 27 13 7:40 AM

I’m the first to admit I don’t know squat about welding. I know there is brazing for bronze as well as welding—I would think a weld would be as strong as the surrounding material, but again, I don’t know. Another thought would be to sleeve the welded joint and weld the sleeve as well. Have the sleeve extend up into the boat so you would have to enlarge the rudder post opening in the keel a bit, but not far enough to require a larger stuffing box.

As for the rudder shoe, having seen a number of them now, I believe the shoe on my B29 is not the normal shoe—maybe because my boat was build close to the end of the model run they changed it. Your shoe is more common. The hole going all the way through receives the pintel, and you drop the pintel out the bottom to then remove the rudder. If she were my boat, my suggestion would be to grind both surfaces flat and fair like on my B29 and use a large Teflon washer between them to eliminate any abrasion. You will need some new bronze stock to fashion a new pintel (www.onlinemetals.com is a good source).The top of the pintel needs to be rounded to fit the gudgeon. Assuming the gudgeon is ok on the bottom of your rudder, you should be back in business. When you put everything back together, fill the gudgeon with waterproof grease.

Cheers,

David

Restoring a Bristol 29 in my backyard. www.bristol29.com

Quote    Reply   
avatar

cadetrob

Able Bodied Seaman

Posts: 22

#28 [url]

Mar 28 13 8:28 PM


http://s3.photobucket.com/user/cadetrob/library/B29%20Rudder?page=1

Hi David, I was working on the shoe today and removed the cross bolt (athwartship bolt) for the pintel and noticed that the bottom of the shoe is cracked and chewed up and there is some play. You can see the cracks in the link above.  For example, if I put a screwdriver in the pintel cylinder and press downward, the bottom of the shoe separates slightly from the top half. What would you do if that were your shoe? The yard owner stated that he would build some sort of external strap to hold the weak shoe bottom. He also recommended that I tap the rudder post that's in the rudder in order to screw on additional rudder stock. What do you think of that? 

The x-ray tech took multiple area shots of the B29 rudder as he was unable to take on full shot of it...but he pieced together all the shots and this is what he came up with. 

After looking at your rudder pics and at the x-ray, I'm thinking the bend in my rudder post (stub) is by design and not by rudder damage from it falling off the shoe/pintel. What do you think?

Thanks, Rob



Quote    Reply   
Remove this ad

#29 [url]

Mar 29 13 5:02 AM




Hi Rob,

Seeing the whole rudder this way I agree with you--the rudder post bend takes the angle needed to align with the bottom half of the post. I'd sure like to know the real truth about what happened with your rudder. But in any event, here are some things that come to mind.
1. You need to check the soundness of the rudder tube inside the boat. If the rudder was bent, the tube probably was cracked. I know of at least one B29 in North Florida that had that problem. If the tube is cracked you can sister it by slipping another fiberglass tube over it with liberal use of epoxy, but finding the correct combination of sizes for the larger stuffing box will be challenging.
2. I don't think taping and attaching a new rudder post mechanically will be nearly strong enough. After thinking about it I don't think welding will answer either (it will heat up the rudder post embedded in the rudder and the surrounding fiberglass too much). 
3. If this were my rudder, with the xrays you have in hand, I would open up the top part of the rudder around the area of the broken rudder post, using a Dremel tool, cut away the glass around it and remove it. Then, take it and the new rudder post (and the composite xray) to a good metal shop and have them make the correct bend and weld in place the support structure pins (I can give you the length you need for the new rudder post, or you can measure it easily.) You could make the new post out of bronze or out of solid stainless, but do not be tempted to use pipe--it must be solid. Finally I'd position the new rudder post in place, and fill it flush to the top of the metal with epoxy, and then build up layers of bi-axial glass and epoxy to bring it flush with the surrounding rudder.
4. To repair the shoe, I would not listen to your yard--their solution is no repair, just a patch and what will happen eventually is the shoe will crack in two inside the external strapping and the bottom of the rudder will have enough play to vibrate and perhaps even jam or your pintel will drop out completely. The proper solution is to carefully grind away about 1/3 inch of the outside of the shoe and the surrounding keel back about 18 inches. Get all the way through the gelcoat and into good clean glass. Clean it well with acetone and then wrap layers of 24oz biax tape and epoxy around it, layer upon layer--probably 6 to 8 layers--to bring it back flush with the rest of the keel. Use a teflon dowel (from mcmastercarr.com) the size of the pintel to create a mold for the pintel and fill around it with epoxy to create a good clean hole for the pintel. The dowel will tap out after the epoxy has cured.

That's what I would do. 

Cheers,

David


Restoring a Bristol 29 in my backyard. www.bristol29.com

Quote    Reply   
avatar

cadetrob

Able Bodied Seaman

Posts: 22

#30 [url]

Mar 29 13 6:24 AM


Thanks David, I think that sounds like the better solution for the rudder post (taking all out and putting back in). Is there a particular stainless steel that you recommend? Do you prefer ss over bronze? That would be great if you could tell me the post length......it will give me confidence for any of my measurements :-)  And I'm going to follow your advice on the shoe too. Do you think I should put a dowel for the cross bolt too or should I just fill it in and then drill new holes for it later?  What do you think of having a new shoe machined.....something similar to the shoe below? The yard guy seemed to think that the shoe was pre-made out of fiberglass and then bolted onto the keel. He pointed out the paint stress crack on the side of the shoe/keel that you can see in my link. Thanks much.... I think I would have given up on the boat if it were not for you and your restoration site.



Quote    Reply   

#32 [url]

Mar 29 13 11:11 AM



Rob,

The crack in this shot: 

 photo IMAG4464.jpg

I'm not at all sure that is any kind of stress fracture, it could just as easily be a crack in the flaking old bottom paint. You will have to sand that area down to the gelcoat to see what's going on. I'm not a fan of the bolt on rudder shoe you show in the photos. A much stronger solution would be as I outlined above, using epoxy and biax tape. 
I don't think you will have to worry about the hole for the locking bolt: it isn't a strength factor, just a means of locking the pintel in place. 
Either stainless or bronze would work fine. Bronze is softer and may be easier to bend. 

The two measurements I can give you are: the distance from the top of the rudder to the bottom of the boat is 1". The distance from the top surface of the cockpit sole to the top of the rudder post (measured along the middle of the post) is 5-1/2 inches. Measured along the forward side of the rudder post, it is 7". Just run your tape up the rudder post tube and measure the distance from the bottom to the top of the cockpit sole, add my two measurements to it and you have the length of rudder post (plus of course the length buried inside the rudder).

Cheers,

David

Restoring a Bristol 29 in my backyard. www.bristol29.com

Quote    Reply   
avatar

cadetrob

Able Bodied Seaman

Posts: 22

#33 [url]

Mar 30 13 8:13 AM

Do you recommend the naval bronze (that I saw on onlinemetals) for the post?  Thanks again!  Dreaming of seeing this boat being launched, Rob

Quote    Reply   

#34 [url]

Mar 30 13 12:35 PM

Either aluminum bronze or silicon bronze is suitable (you want the lowest percentage of zinc in the alloy):


Aluminum Bronze Material Property Data Sheet

Do you need custom fasteners created with Aluminum Bronze? Since our inception, Vegas Fastener Manufacturing has met every challenge of providing Quality, Timely, Cost-effective solutions for specialty fastener applications. Every product is built to your specifications, using your prints if necessary.Below are the technical specifications of the Aluminum Bronze Bar Stock we have available to meet your needs.

 


Aluminum Bronze, UNS C61300

Subcategory: Bronze; Copper Alloy; Metal; Nonferrous Metal

Key Words: CDA 613

Component   Wt. %
Al6 - 7.5 
Cu88.5 - 91.5 
Fe2 - 3 
MnMax 0.1 
OtherMax 0.05 
PbMax 0.01 
Sn0.02 - 0.5 
ZnMax 0.05 

Material Notes: Good to excellent corrosion resistance. Good hot and cold formability. Fair to poor machinability

Applications: nuts, bolts, stringers and threaded members, corrosion resistant vessels and tanks, structural components, machine parts, condenser tube and piping systems, marine protective sheathing and fasteners, munitions mixing troughs and blending chambers.


Low-silicon bronze B, UNS C65100, OSO35 Temper rod


Subcategory: Bronze; Copper Alloy; Metal; Nonferrous Metal

Key Words: CDA 651, ISO CuSi1, CEN C115C

Component   Wt. %
Cu98.5 
FeMax 0.8 
MnMax 0.7 
PbMax 0.05 
Si0.8 - 2 
ZnMax 1.5 

Material Notes: Good to excellent corrosion resistance. Excellent hot and cold workability. Fabricated by forming and bending, heading and upsetting, hot forging and pressing, roll threading and knurling, squeezing and swaging.

Applications: hydraulic pressure lines, anchor screws, bolts, cable clamps, cap screws, machine screws, marine hardware, nuts, pole-line hardware, rivets, U-bolts, electrical conduits, heat exchanger tubing, welding rod.

Restoring a Bristol 29 in my backyard. www.bristol29.com

Quote    Reply   
Add Reply

Quick Reply

bbcode help