SplineWeights.com Make Your Own Spline Weights

[SplineWeights]

I own splineweights.com and have been making ducks / whales for a year now. I am now offering instructions on how to make your own at www.splineweights.com

Thanks

[Nels Tomlinson]

Originally Posted by SplineWeights

I am now offering instructions on how to make your own at www.splineweights.com

That's good news about the instructions.

I've been experimenting with using a high temperature, two part silicone as the mold material. I'll let you know how it all works out.

By the way, is the 1/8 brass rod really strong enough? That's the thickest I can find here in town, but it seems to bend way too easily.

Nels

[SplineWeights]

A 1/8th rod is strong enough to hold the spline in place... we also offer a 3/8th rod but its more for looks since the 1/8th rod looks kinda skinny compared to the 3.5 pound weight. This mold you are experimenting with... is it a one time shot or reusable?

[Nels Tomlinson]

Originally Posted by SplineWeights

This mold you are experimenting with... is it a one time shot or reusable?

Well, if the two part silicone works as advertised, it should be reusable. It is supposed to tolerate 700 degree F pours, and if it doesn't, I've found another which is supposed to tolerate 800 degree F pours. As I said, I'll let you know how it turns out. It'll be a week or two, probably.

[Robert Gainer]

Is this the stuff that is used to cast a wax pattern that is then used in “lost wax casting” in green sand?

[Nels Tomlinson]

Originally Posted by Robert Gainer

Is this the stuff that is used to cast a wax pattern that is then used in “lost wax casting” in green sand?

No, it's a two part silicone rubber which is supposed to be able to stand having lead poured into it.

I've carved a male pattern, from wood, to a shape which feels nice and should pop out nicely from the mold. I've made a wooden box to hold the silicone, and will shortly mix the silicone, pour it into the box, shove the pattern into it, and let it harden. Assuming that the petroleum jelly is smeared thickly enough on the pattern and the box, I should be able to pop the pattern out of the mold, and the mold out of the box. I want the mold to pop out of the box to make it easier to get it off the casting: the silicone should be slightly flexible, which might ease removing the pattern and casting, but that means it needs the box to support it.

Then, I will place the mold in the box, pour in some lead, and see what comes of it. We'll find out how well it holds up to the temperature, and for how long.

[SplineWeights]

Well as you know, I am sure, Lead BEGINS to melt at 620 F. For a good pour for a 3 pound weight I found 900-1000F to be ideal. You can pour begining at around 700F but the results arent pretty on a consistent basis

[Nels Tomlinson]

Originally Posted by SplineWeights

Well as you know, I am sure, Lead BEGINS to melt at 620 F. For a good pour for a 3 pound weight I found 900-1000F to be ideal. You can pour begining at around 700F but the results arent pretty on a consistent basis

Well, that's why I say we'll see how it all turns out. Since I'm not planning on selling these, I really don't need pretty to the extent you probably do. If I were intending to get more than one set of 14 out of this, I'd probably make an aluminum mold out of old pots.

I tried using some of the one part high temperature RTV stuff, which cures on exposure to the moisture in air. It works, sort of, but the interior got slimy after the first pour, and it kept getting worse. I think it's only for use up to 500 degrees F or so, so no surprise. Also, I had trouble with getting thick layers to cure. I did get half a dozen weights cast, but the ``pretty'' wasn't quite up to my very low standards, and I couldn't support it adequately, so the sides bowed out a bit and I had fat whales. This new effort will definitely work better than _that_!

The phase diagram for the Pb:Sb alloy (wheel weights are supposed to be about 97:3) suggests that my wheel weights should melt about 50 degrees F lower than pure lead. I'm not sure whether that will really help. It might save the silicone, might not help with the ``pretty''.

Maybe this weekend I can make time to mix and pour the silicone and give it a try.

[SplineWeights]

If it doesnt work I suggest you go to the internet for a good receipe for green sand and do it that way...

[Robert Gainer]

When I was a teenager and could not purchase ducks (no money) I made a pattern from wood and then made a mold from plaster of paris. It would hold up for five or six pours and then I would make a new mold from the wood pattern. The only problem I found was that you needed to dry the plaster mold in an oven or the molten lead would make so much steam that the mold would break when you did the first pour.

As far as I know the only silicone that is used in casting is to make a mold for wax copies that are then used in the lost wax process. You need green sand to pack around the wax master and then all you do is add a hole to the green sand for adding the lead and a second hole to let out the air and steam.

[Richard Hillsid]

Originally Posted by Robert Gainer

When I was a teenager and could not purchase ducks (no money)

Same thing, i pored lead into tuna cans, drove in a nail through the side. before the pore, the trik to remove them was to cut of the upper edge of the can that is invard before the pour or after, just dont fill to the brim.

Made my own scuba weights the same way, bolt on type, but then started with plaster molds to get a nice copy of one I bought.

And then came 2,5 ton keels etc.

[countart]

Just wondering if the production is up and running and if I can make a purchase.

[westlawn5554X]

http://www.edsonmarine.com/

[Frosty]

Im sorry I only speak English. I was born there so im pretty good. What the hell is 'spline weights' Ducks? what sort of ducks? and whales What the ????

[westlawn5554X]

http://www.westlawn.edu/forum/forum.asp?FORUM_ID=36

There’s another nice detail about the Edson spline weights. Because they’re tumbled bronze they don’t have any paint. Every single painted spline weight I’ve worked with eventually had the paint chip and wear off. This doesn’t look so good and the paint chips can flake off an mark up the drawings. This will never happen with the Edson weights.

By the way--in the old days--the paint chips off of the spline weights could be such a problem (because of scuffing and marking the drawing underneath) that some designers actually made little cotton "booties" to fit over their spline weights. These had to be removable because the "booties" would get gray from the pencil lead and had to be washed from time to time. I have an article about making the "booties" somewhere, but I won't bother to dig it up as you certainly will never need them with the unpainted, tumbled-bronze Edson weights.

You can definitely start with only 6 spline weights and gradually acquire more weights later. That’s what I did years back. In fact, you can usually use a couple of heavy books, or mugs or cups filled with scrap bolts, or similar, at the spline's ends to make up 2 extra weights—effectively 8. You can get by OK that way for a while. Shifing some weights around to draw a complete line will also effectively increase the number of weghts; a passable work-around.

If you end up doing a lot of manual lines fairing the ideal number of spline weights is 12; though, I actually have 18 spline weights. These days, however, I no longer need more than 12, as large hand-faired drawings—are now done, instead, in a hull-fairing program. I do use the full set of 12 spline weights fairly often, when doing the preliminary lines. See the Student Guide 2nd Edition, Section 9, starting on page 125 (particularly the bottom of page 127). Also see Appendix D, page 160.

Quote from famous westlawn mentor... if you have acess to the forum use the link above.

In Westlawn all is clearly explained in detail and they have 2 blueprint for making your own cheaply but I dont think I have permission to post does two attachment sorry.

Look on the bright side try figure on the picture below and find the odd duck out... it would use a most part of your time to test your mind. Back to you JACK.