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#1
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![]() "James Johnson" writes: It's hard finding lead keel casting information. If you don't mind what did you use to melt the lead? snip I don't know where you are located, but I no longer need my melting equipment including ingot molds that produce 30 # pigs. Have 2, 500,000 BTU propane burners and a melting pot that holds about 900 lbs. If interested, I'm in Los Angeles. Lew |
#2
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Unfortunately I'm in Maryland, the freight costs would probably make the total
cost prohibitive. Otherwise I would be very interested. In answering questions on several other replies: The point about trim is valid but the penciled in changes to the factory blueprints have the weight distribution (it specifies what weight to be put where) pretty much matches that of the external ballast keel, and several other owners who removed the ballast to lighten the boat for afternoon racing reported that the boat was excessively tender but trim was OK. I'm wondering if the design was originally drawn up for lead and the yard substituted iron, and went back to the designer after complaints for advice. The factory blueprints don't spec the weight of the external ballast, but the internal ballast is detailed. The boat was built by Werf Gusto in Holland in 1961 and designed by Bill Tripp. The blueprints are in Dutch but the internal ballast is penciled in English. The shape of the external ballast is about 4' or so long, around 8" high, and 8" wide with a 1" centerboard slot making it look like a stretched 'U', so cautions about alloys for fins (with their high bending loads) I don't think would apply. I was going to pull the keel anyway to inspect/replace the keel bolts because of the amount of rust at the hull joint. To drain the lead from the melting pot I was thinking about something I read about by Larry Pardey. He used a cast iron bathtub and had a plumbing pipe elbow welded to the drain. Screwed into the elbow was an 'L' shaped piece of water pipe. He used a chain to lower one end of the 'L' to start the pour, and raised it to stop it, with the 'L' rotating by the threads at the elbow. His book about classic boat construction is one of the few references I found. JJ On Fri, 18 Jun 2004 16:40:52 GMT, "Lew Hodgett" wrote: "James Johnson" writes: It's hard finding lead keel casting information. If you don't mind what did you use to melt the lead? snip I don't know where you are located, but I no longer need my melting equipment including ingot molds that produce 30 # pigs. Have 2, 500,000 BTU propane burners and a melting pot that holds about 900 lbs. If interested, I'm in Los Angeles. Lew James Johnson remove the "dot" from after sail in email address to reply |
#3
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![]() James Johnson wrote: The shape of the external ballast is about 4' or so long, around 8" high, and 8" wide with a 1" centerboard slot making it look like a stretched 'U', so cautions about alloys for fins (with their high bending loads) I don't think would apply. I was going to pull the keel anyway to inspect/replace the keel bolts because of the amount of rust at the hull joint. I would still go for at least 50% wheel weights. As I said pure lead is very soft and if the external keel is bolted on, the normal movement will wallow out the lead around the bolts/washers and cause the keel/hull joint to open. 50% wheel weight lead mixed with miscellaneous scrap will insure you get 1.5 to 2% antimony and harden it up enough to prevent that. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#4
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Glenn says:
I would still go for at least 50% wheel weights. snip a little 50% wheel weight lead mixed with miscellaneous scrap will insure you get 1.5 to 2% antimony and harden it up enough to prevent that. Heed this man - he speaks sense and wisdom born of practical experience. Any good foundry will tell you the same, as will any builder or designer. You do NOT want your keel falling off.... Steve Stephen C. Baker - Yacht Designer http://members.aol.com/SailDesign/pr...cbweb/home.htm |
#5
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On Sat, 19 Jun 2004 16:29:26 -0400, Glenn Ashmore wrote:
James Johnson wrote: The shape of the external ballast is about 4' or so long, around 8" high, and 8" wide with a 1" centerboard slot making it look like a stretched 'U', so cautions about alloys for fins (with their high bending loads) I don't think would apply. I was going to pull the keel anyway to inspect/replace the keel bolts because of the amount of rust at the hull joint. Thanks Glenn for that tip. I was planning on going the wheel weight route for cost reasons. I'll also keep your points in mind for why I shouldn't just go out and buy scrap lead. JJ I would still go for at least 50% wheel weights. As I said pure lead is very soft and if the external keel is bolted on, the normal movement will wallow out the lead around the bolts/washers and cause the keel/hull joint to open. 50% wheel weight lead mixed with miscellaneous scrap will insure you get 1.5 to 2% antimony and harden it up enough to prevent that. James Johnson remove the "dot" from after sail in email address to reply |
#6
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"James Johnson" writes:
would probably make the total cost prohibitive. Otherwise I would be very interested. Then find an asphalt contractor who does parking lots. They use a 500,000 BTU hand held burner /w/ a hose connected to a 20 lb propane bottle to seal the edges of the asphalt joints. Find out who sells them in your area. About $60 will get you the whole thing. SFWIW, a 500,000 BTU burner is just about minimum if you expect to get anything done, based on my experience. IMHO, screw any cobbled together molten lead control valves. They are destined to be a bigger PITA than they are worth. Buy a plumber's ladle, it holds about 8 lbs of molten lead, and ladle the lead from the molten pot directly into the mold. (If you can believe it, I probably did close to 30,000 lbs this way, one ladle at a time.) Working with molten lead can be a little tricky. It transitions from solid to liquid rather slowly. It transitions from liquid to solid very quickly, but is still very dangerous if not handled properly. A 500,000 BTU flame thrower working for you settles a lot of problems before they develop. A word of CAUTION: NEVER IMPINGE A OPEN FLAME DIRECTLY ON LEAD. NEVER. Find a piece of angle iron, 4"x4"x1/4"x48"-60" long. Weld in 1/4" dividers on 12" intervals. The above ingot mold will produce 30 lb triangular lead pigs, 12" long, that can be stacked in an interlocked pattern for trim ballast. HTH Lew |
#7
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On Sun, 20 Jun 2004 00:27:45 GMT, "Lew Hodgett"
wrote: "James Johnson" writes: would probably make the total cost prohibitive. Otherwise I would be very interested. Then find an asphalt contractor who does parking lots. They use a 500,000 BTU hand held burner /w/ a hose connected to a 20 lb propane bottle to seal the edges of the asphalt joints. Find out who sells them in your area. About $60 will get you the whole thing. SFWIW, a 500,000 BTU burner is just about minimum if you expect to get anything done, based on my experience. Thanks for the tip. I will look for one of those. IMHO, screw any cobbled together molten lead control valves. They are destined to be a bigger PITA than they are worth. Buy a plumber's ladle, it holds about 8 lbs of molten lead, and ladle the lead from the molten pot directly into the mold. How long did that take? And did your arms look like Popeye's when you were done? ;-) Thank goodness I am only thinking about casting 1850 pounds. (If you can believe it, I probably did close to 30,000 lbs this way, one ladle at a time.) Working with molten lead can be a little tricky. It transitions from solid to liquid rather slowly. It transitions from liquid to solid very quickly, but is still very dangerous if not handled properly. The largest lead casting I have done has been 40 pound centerboard weights for a sailing dingy, and I noticed that behavior. A 500,000 BTU flame thrower working for you settles a lot of problems before they develop. A word of CAUTION: NEVER IMPINGE A OPEN FLAME DIRECTLY ON LEAD. I suppose this is for avoiding the breathing of lead fumes? When I did the dinghy weights I used an air supplied respirator, flame retardant coveralls, welders gloves, and heavy boots. May be a bit of overkill but before I became a programmer I worked in nuclear plants for 20 years as a systems operator and health physics specialist, and I have a strong aversion to riding lying down in the back of an ambulance. (Did that once, it motivated me to go back to school and get out of the power industry) NEVER. Find a piece of angle iron, 4"x4"x1/4"x48"-60" long. Weld in 1/4" dividers on 12" intervals. The above ingot mold will produce 30 lb triangular lead pigs, 12" long, that can be stacked in an interlocked pattern for trim ballast. HTH Lew Thanks for all the tips. JJ P,S, I'm not usually up at this time of night. But was paged with a production problem that turned out to be system related and I am waiting on the system administers to call me back. (If I had root privileges I could have done it myself but application programmers are not allowed to step into sys admin territory) James Johnson remove the "dot" from after sail in email address to reply |
#8
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James Johnson ) writes:
On Sun, 20 Jun 2004 00:27:45 GMT, "Lew Hodgett" wrote: "James Johnson" writes: would probably make the total cost prohibitive. Otherwise I would be very interested. Then find an asphalt contractor who does parking lots. They use a 500,000 BTU hand held burner /w/ a hose connected to a 20 lb propane bottle to seal the edges of the asphalt joints. roofers also use propane heaters. just visit your local equipment rental outlet for this kind of thing. -- ------------------------------------------------------------------------------ William R Watt National Capital FreeNet Ottawa's free community network homepage: www.ncf.ca/~ag384/top.htm warning: non-freenet email must have "notspam" in subject or it's returned |
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