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Discussion Starter #181
brush it on and into the shape to be molded. I generally do this to avoid having voids and bubbles at the surface of the mold.
Couple reasons I didn't:

1 - Mine wouldn't brush, it was just bathroom caulking.
2 - I put it in a plastic tube, and then used a floor jack to press that onto the shaft.

I got my alignment bad, and my wall width poor, so I just threw away about 20% of the edge, but otherwise it turned out great with no voids or bubbles. It copied the milling details from the shaft and the surface finish, so, I presume it's good.

It looks like I can get away without doing an early brushing, or using a vacuum chamber.



-do some more research on making a mold with an outer support (mother mold or a mold box).
For my next iteration, I was thinking, a beer can. Then I can be reasonably confident that it goes back into the same shape.

But, plaster inside a square box sounds like a better solution. Problem is that there's not a lot of room around the driveshaft to build a box, it's in a recessed hole.

I kind of like having the play-dough consistency, I was going to make my next one upside down because I'm getting sick of reaching in a narrow gap between the milk crates that support the motor.

have you been using mold release? Even silicone will stick to metal and tear when you try to remove it if you don't use mold release.
That's the biggest advantage of the corn starch dough-like mix I've been using. It doesn't stick. Only a little bit to the bottom of the shaft. I've been using baby powder, silicone brake grease, and penetrating oil (each, not together) during various mold pours. The brake grease seems the best.

What's mold release made from?

The easy thing would be to take 2.5" plumbing PVC pipe about 4-5" long (nice flat cuts on the ends, no angles!) and slice it open one end to the other (this allows you to stick a screwdriver in it and pry it open) then cover the split with duct tape.
I independently came up with that method as the next thing I want to try. My PVC is a bit small though, and I don't want to buy an 8' just for an enclosure. Maybe Home Depot's got a nipple or something I can use.

-if, however, you want a wax female of the male axle shaft, you need to make an intermediate casting.
I thought about that, but, no. I'm only making one of these, I don't want to put too much effort in.

My intermediate will just be a plaster pillar of the driveshaft. I don't mind having to make a new one every time I attempt the Zamak casting.

...

Thanks for the advice. I'm going to try again tonight or tomorrow.
 

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Detritus Maximus
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Viscosity is the enemy of the brush method. Works great with mold silicone, not so much with caulk, especially if it is acrylic latex.

Even with actual molding/casting materials I'm not crazy about vacuum or pressure. In fact, vacuum is generally used to expand and pop air bubbles in mixed silicone before pouring when making the mold. It reduces those bubbles and voids in the mold. Pressure is generally used to shrink the bubbles and voids in the material (usually resin) being poured into a mold to make the copy itself. If there are bubbles and voids in the mold, pressure during casting a copy will collapse them and create warts on the casting. My experience is both or neither.

Jigging everything up to make the mold can be very trying. I've been lucky that all mine have been on a bench. I have seen this vs on how they make molds of architectural stone work on old buildings to reproduce parts. It's pretty impressive. They use a fairly thick urethane.

There are various types of mold release. The stuff I've used was in a spray can and sold thru the silicone suppliers. A friend swears by talcum powder, but that is best on a flat pour on a workable as you sprinkle it on. It's hard to sprinkle 'up'...

Look for the female to female couplers for connecting pvc pipe in the pvc area. Already have have ends that are square.

I hear you on just making one, but is there a market for more?

I was going to suggest alginate for a mold (like what dentists us) but it shrinks...alot and fast. Some of the silicones/urethane do too, but not as much and over a longer period of time. That is not such a good thing for a spline connector...
 

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Detritus Maximus
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Vaseline can work for a mold release as well.
 

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Discussion Starter #184
A friend swears by talcum powder, but that is best on a flat pour on a workable as you sprinkle it on. It's hard to sprinkle 'up'...
Actual talcum powder doesn't exist anymore, it went the way of asbestos. Baby powder is cornstarch now.

And yeah, sprinkling upwards has been a pain in the ass, gotta volcano enough that it gets everywhere.

I hear you on just making one, but is there a market for more?
With certainty, no.

Even among EV conversions, my choices are odd.

I haven't seen anyone else use a forklift AC motor, all the used forklift motors I've ever heard of anyone finding or using are DC (which used to be the go to cheap conversion, and what I was expecting to find when the scrapyard owner told me he set one aside for me). And then to mate that to a turned down GT transmission output shaft? Nope, my project is certainly unique on several fronts in the world now, and I expect forever.

That is not such a good thing for a spline connector...
Y'know, earlier I was worried about tolerances on EDM, but I was going through my transmission parts last night, and there's a gear with both external and internal gears, and I put the internal one up to it, and there's tons of rotational and jittery play between them. Certainly more than 1 thou, more like, 10 thou. If that's fine, maybe I'm being too strict.

Oh well, trying to stay on target. I've spent the last week reading up on IRS and LSD and rear brake swaps. Step 1 I'll use the parcel shelf for batteries, but when I cut into the rear floorpan to fit the battery boxes, I might as well plan what my "better" rear end may someday be and build accordingly.
 

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Discussion Starter #185
Just for anyone curious about EDM and whether it would work well enough, here's a video explaining how it works and showing some gear cutting. And a D-shaped hold drilling in hardened tool steel.

 

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Discussion Starter #186
Small bits of progress. Haven't been in the shop much and when I do go I mostly sit around and am not sure what to do. Procrastinating, finding other things to do. Pulling parts at the junkyard for other people's vehicles instead of my own, working on theirs instead of mine.

I think I've stalled on the coupler for as much time now as I spent welding the two whole bodies together, still without a good solution.


Coupler Progres:

I made a new spline mold, V2. Used up the entire rest of the silicone tube, figuring I'd used half of it the previous time. Oops, nope, I had enough for the new mold and a tennis ball amount of excess. Oh well. Nice thick walls.



Detail is not as good as V1. I think I overdid it on the corn starch. It has a sandy texture to it. And it didn't release on the bottom of one spline:



Not a big deal, it means my plaster will have extra material, and I can use a knife to shave it back to the right size.

Plaster copies came out okay, few bubbles. Tried vibrating them out using a surplus, err, back massager from the night table, only moderately effective:



Melt-wise... I thought I had lots of cast zinc, pounds and pounds of it. I tested it by leaving little slivers on a stove burner and seeing if they melt. They did, but larger pieces would not. I have aluminum, not zinc or Zamak. I think I want Zamak (almost as strong as cast iron, self-lubricating, stovetop melting temperatures), so now I have to find or buy some from a scrapyard. If not, I can't stovetop melt aluminum, I'd need the furnace.

And knowing I'd be pouring the whole coupler at once, I was worried about having enough battery capacity for the arc furnace. So I called NAPA and asked if I could buy some of their core batteries back for the price of the core. They said sure, and will even let me drop them back off when I'm done and get my core back. Renting batteries for free I suppose.



Out of the 8 I bought, I think 5 were still good. Furnace-wise I think I'm good.

Crucible-wise, I'm waiting for the thrift stores to re-open to pick up a stainless or cast iron pot (and maybe some zamak bathroom fixtures to melt).

I guess I've never even taken a good picture of what I'm trying to do.



I have to do some modification to the transmission output shaft, but how far I turn it down I'm not sure. One consistent diameter. If the motor shaft protrudes 2", I guess I should have 2" of grab length on the transmission shaft. But in my head, the tail housing and motor were almost touching. now that I look at it, they're separated by 4". So, now I need some giant case to enclose all of it, not just a mating plate.

And at that point, am I even saving any weight or length compared to having the whole transmission?


Lots of seemingly-little thing I need to figure out how to actually accomplish. Usually I make progress by just picking one thing and heading in that direction, but there's so many things that all have to be right at the same time:

- To make the coupler, I now have a plaster form for the motor's side. I don't have a form for the transmission side, which could just be a tube, but it has to be the exact size of the transmission shaft, which I should grind down first.

- Then, how do I grind it down consistently without a lathe? Just bench grinder with angle iron to keep it square?

- If my hole on the transmission side of the coupler is wrong, do I have a drill bit big enough to enlarge it? Do I have a chuck large enough to hold it? How do I keep it perfectly centered?

- When I'm making my casting and connecting the plaster splines to the plaster tube, how do I make it centered within driveshaft-required precision (I presume at least 0.001")?

- Can you combine a splined coupler with a taper-lock coupler, or is that going to create too much of a stress riser wherever the slot stops and encourage it to split?

- I haven't even tested if the motor works yet. I haven't finished wiring up my inverter to test it. All this work might be for a motor that I end up not using.


I think the best thing to do is perhaps make the coupler with only the motor side. The rest of it where the transmission shaft goes will be temporarily solid.

Then I can slip the coupler onto the motor, and just use the motor itself as a lathe. I think I use a scribe to find the exact center, then center punch it, center-drill it, then set up some books under a cordless drill (flipping pages is a 0.005" adjustment). A still drill bit should be self-centering on a rotating shaft, I think? It'll pull itself perfectly through the middle?

As usual, everything is more complicated than it seems. Tempted to just go back to welding the shaft and being done with it.


Misc:

Brake lines and fittings arrived. Went with the teflon coated one because it was the only 3/16" line on Amazon Prime. $17 line, $13 fitting.



Snuck in at the tail end of the Sneeze sale at OGTS for about $100 of stuff:
- Door bumpers
- Hood bumpers
- Steering rack boots
- Master cylinder reservoir seals
- Master cylinder hose
- Rear transmission seal
 

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Matt,
Just a thought....have you considered a Roto coupler? Triumphs and Alfas used them, for sure.
Allows for flex and misalignment between shafts.
 

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Discussion Starter #188
Can't clean out the rocker panels without some kind of rod and room to insert it, so, front suspension has to come off. Also, it's the last thing on the car I haven't disassembled yet so, why not. New steering rack boots are in the mail soon from OGTS.

Spent the day doing some editing, no graphics or voiceover, but, not much to say anyway:


Few things:
- I eventually realize there's nuts below the cross member mounts.
- I eventually figure out that when you're wrench on one side, socket on the other, put the wrench on the side so gravity keeps it put rather than pulls it away.
- Immediately afterwards, no room for a socket on those front nuts. Barely even room for a wrench.
- I wasn't using either of my two big impacts because it was 3am and the neighbors had their motorhome parked across their driveway and power run to it, so I think they had company staying over.
- Second bolt was badly bent, not my doing.
- Fourth nut was a 17mm instead of a 15mm, just to make things difficult.
- There are spacer-like things under the mounts. Authentic or necessary?
 

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- There are spacer-like things under the mounts. Authentic or necessary?
Spacers are authentic. And necessary. I think I have a pair of not-too-bad ones somewhere, when the time comes. Or you can make a new pair, just need to replicate the thickness fairly closely.

...and I think you just wanted to show off your Princess Auto lift thing.... ;)
 

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Discussion Starter #190
...and I think you just wanted to show off your Princess Auto lift thing.... ;)
$50. Can't go wrong. It's amazing. Comes with the motorbike rail grabbers too (which were so crooked they either didn't slide over the frame, or were so loose they wouldn't lock onto it, had to adjust them with a vice and sledgehammer). Wish I'd bought it years ago.

You'd mentioned not to take off the front suspension unless I had to, as it was hell to put it back on with one person. That was certainly true of the rear suspension, balancing the diff on a floor jack and holding the hubs up with milk crates. I don't think that's going to be a problem again.

It's rated for 500lbs, but that's "cheap tool rating" lbs, so I figured 250 would be pushing it until I took it out of the box.

Well, went to brakes on my van the other night, and the factory screwjack suddenly went sideways 2". Ran and grabbed the motorcycle lift as a better-than-nothing option before the van came down on the hub and punched what was left of the jack through the floorpan. Couldn't get it near the jackpoint (screwjack was stuck), so I was lifting almost the whole side of the van up. Gotta be close to 2000 lbs before the the front came up, didn't even feel like it was struggling.

It's a scissor lift too, so it doesn't shift and squirl around on you as it rises like a hydraulic cantilever jack does. Nor is it a pain in the ass to fine tune, a little up, and little down, no problem.

The $10 rolling platform underneath it though, rated for 500lbs, not good for more than that. Pizza guy's wheel fell off (balljoint separated) in the middle of the road, tried throwing a 2x6 across it and putting it under what was left of the hub to drag it into a parking spot. Didn't crush on impact, but pushing the car 2 feet bisected the caster bearings.

Not a problem, I rarely need to both lift/lower and move things over 500lbs anyway.
 

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Discussion Starter #192
Order arrived from OGTS. My shopping cart had a few hundred worth of stuff during their Sneeze sale, but it paired down to $58 by the time I ordered. I expected shipping for 1lb of little things from the US to be like, $10 at most.

I guess I wasn't really thinking, I don't need any of this stuff now and the savings from the Sneeze sale (after I pared it down) were completely swamped by the shipping costs of ordering now.

Even combining shipping with someone else local, a 4lb box was $48 (US) shipping + $18 CAD in duty. $80 CAD to ship 4lbs to Canada. At least we saved money by splitting that to ~$40 each, but, ugh. This is why many Canadians just ship to the border and then go pick it up themselves. If you don't mind the drive, even small orders cost as much as a tank of gas.

Anyway, mmmm, the smell of new rubbers:

- Steering boots
- Master cylinder reservoir seals
- Master cylinder tube
- Door and hood bumpers
- Transmission output seal



Also, I did a little comparison between the window regulator motors for Honda Civics vs. Dodge Caravans. I'll post more about this in a dedicated thread, but:



If you exclude the bearings and the end caps and all that and compare the actual motor (where it gets its power), the Caravan is about 150% the power of the Civic. So I might swap civic ones for Caravan ones (or any other cable-driven regulator, those are just the two vehicles I've been taking apart lately).

This might also mean it's geared differently and just moves faster rather than more powerfully, but, meh. Either was, beefier motor.


Aluminum Coupler:

- Now that I'm trying to pour a beer-can-sized amount of metal, (verus the golf ball sized amount of copper before), I can't just use firebrick.

- That's annoying, because I don't want to order a graphite crucible just for this little project. I need something cheap that'll hold together above aluminum melting temp.

- I settled on a stainless chaffing tray. This kind of thing:



- I melted some aluminum into it, but the metal was so thin, every time I accidentally bumped the sides with the torch it burned a pencil-sized hole through. Also it had trouble holding temperature. I ran out of battery juice before I had much melted.

- I made my first green-sand mold by mixing sand and ground up kitty litter, packing it into a flower pot around an aerosol can for the shape, and then set my plaster spline at the bottom. Wait, is aluminum heavier than plaster? Is the plaster thing just going to bob up through the metal like a cork? Hmm. Too lazy to anchor it with a bolt.



- I called up my fire extinguisher guy and asked him if he ever has old extinguishers for disposal. He said sure and dropped off a handful. The steel is thick enough that it makes good crucibles.



- I chopped the slimmest extinguisher in half and set it into a coffee tin, filled the sides with sand. Hopefully to give it enough thermal insulation to hold the heat. Melted a bunch more aluminum, but still ran out of juice.



- I noticed the can took like an hour to get hot, so I thought, what if I pre-heat the whole can/sand/crucible on a stovetop for an hour or two first, so that it's pre-heated and won't drain batteries. So I did that.

... and it worked!

Sort of.

Problems:

1 - Normally in a combustion furnace you have gas, or CO2 from the burnt fuel. This sort of replaces oxygen. That's good, because oxygen bonds to the molten metal and creates dross, a waste that has to be scraped off before you pour.

Also, the temperatures are low, 3600'F max for propane (and less by the time it touches anything). The hotter the temperature, the more aggressively oxygen will bond to it.

Also, with a combustion furnace you heat the vessel, not the material, so if a layer of oxide forms above the pool, that's okay.

Also, you heat from the bottom up, so it all melts.

With a carbon arc torch, you have regular air everywhere. You have 36,000'F (!) plasma. You heat the material itself, by conducting through the material, the surface of which is already corroded and doesn't want to conduct so the arc keeps going out unless you poke or stir it, oxidizing a bigger and bigger surface scab of waste material. And, heat has to work its way down via conduction, so the bottom is solid and the top is liquid.

All this adds up to mean that the amount of material wasted is like 30% of what you want to pour. You have to scrape it off right before you pour.


2 - I didn't realize how vacuum-packed sand would get around a smooth steel crucible. I used up every last bit of energy in the batteries melting as much material as I could, to as high a temperature as I could. Finally I'm ready to pour, I scrap the dross away, grab the crucible with pliers... the whole coffee can lifts up. I can't shake it loose.

I end up having to stab the sand with a screwdriver a dozen times to make it let go of the crucible. Meanwhile the lid is off and it's rapidly cooling.

I go to pour, and it's just barely at the melting point now. I dump it into the mold, which boils off a little steam inside the liquid metal, cause it to belch upwards to vent. The top of the molten metal collapses down after the air releases, then belches again. Up then down. A third belch... and it only goes part way back down. The metal is solid.

I tried to add more, just so the weight of the incoming metal would pop the bubble and fill the void, but, the bottom 1/3 of the crucible had turned solid.



The casting filled the mold pretty much to the brim, more than it needed to.

So, I broke out the casting and inspected it. Somehow I never took pics of this. I could tell the balance point was almost exactly at the end of the gear splines, which meant the air bubble on the "solid" half must have been almost the size as the whole splined area.

I cut the top off the "solid" end and revealed...



:/ Yep.

Giant air pocket.

I don't think it's a good idea to just pour more metal into that hole, I think you generally have to cast everything at the same time. You can even see there's a couple layers on top where it burped and froze.

Not bad for a first attempt.

Flipped it over cut the rough sandy texture off, and had a good look at the splined side:



... not bad!

The edge needs to have a taper filed into it, it's still got the saw burrs.

Measuring, it's about 0.003" smaller than the motor shaft. Meaning... must still have some crust on the edge interfering with my calipers, or, it's actually slightly small.

I was able to hammer it on 1/4" pretty easily, letting the motor splines shape the coupler's splines a little bit, but I'd rather not be hammering on the motor.

As a proof of concept, I'd call that a success. This looks to be technically possible to do with aluminum.

...

Zamak Coupler:

- I hate aluminum. It's scummy, surface is crummy, it oxidizes badly, it's weak. It melts at a high temp. I don't want it.

- Die-Cast Zinc/Zamak is as strong as cast-iron, surface finish is great, it pours well, it doesn't oxidize badly, and it melts at stovetop temperatures apparently.

- I rounded up every bit of die-cast zamak I could find. Conduit couplers, bathroom towel rod holders, some V-pulleys from a treadmill CVT, some plumbing fittings, a 2-hole punch, railing brackets, chainlink fence toppers, etc. I might barely have enough zamak to make this work. Hard to find, it seems with improved technology, lots of stuff is cast aluminum these days.

- Bought a cheap fried-egg-sized cast iron pan for a crucible and tested whether zamak actually melts at stovetop temperatures.

- Just barely... barely... on my little portable electric burner, but it does. I test-melted as much zinc as I could fit in that little pan (about 1/3). Seems to work.

- Dumped the zinc into a steel pan to make an ingot for the next time I melt. Zinc is 3x as heavy as aluminum so, I don't trust the plaster spline thing to not cork up without being anchored.


...

Next up, more sand, another mold, and an attempt at a zinc coupler. I'd like that to work instead of aluminum if possible.
 

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Discussion Starter #193 (Edited)
Writing updates just to get myself back into things.

Brakes:

I had a brake booster, I disassembled it, but I couldn't figure out how to unbolt the large black vacuum fitting. It has a hexagonal based to it, so obviously it's to be threaded and unthreaded, right?

Wait, no? Oops. It's not suppose to be loose from being spun? Well now I'm not sure it'll hold a vacuum.

Keith pulled a vacuum on it for me and said it held, but he was skeptical of it.

I might try to glob silicone around it to seal it.

Plan B, years ago Keith bought what was supposed to be a GT brake booster for his car, turns out it was a Manta (?) booster instead. But they're 95% the same it appears. Just need to buy a hex coupler and either tap or fabricate it myself to match the one on the GT. Plus, it's supposedly new. And he gave it to me.



It also hasn't been sandblasted by Arizona. So, I'll probably do that. Now I just have to actually put the brakes back together and bend the lines and I'll be done.

...

Casting:

No progress on casting, but I did some research on reforming the slag/dross back into useful metal. Everyone says don't bother, throw it away, you need huge amounts of electricity to do it. But all these people have gas furnaces. I have an electric furnace. So I looked up the process:



It's exactly my melting setup, but with reverse polarity. You liquify the slag (Aluminum oxide, and I presume the same for zinc), then put power through it. The idea is that the oxygen bonds to the consumable graphite rods, forming CO2, and leaves the pure, unoxidized metal behind.

So what I was doing by creating a furnace, was the opposide. I was forcibly bonding oxygen to the metal using electricity. No wonder I had so much dross.

My polarity makes sense for, for example, stick welding, because the heat is generated mostly on the positive side where the electrons "land". And I wanted the heat generated in the melt, not in the graphite rod. So, it made sense for that, but, I created an oxidation machine basically, rapidly contaminating my own melt. I guess I need to sacrifice more graphite, lose heat, and keep the slag from forming by switching polarity from now on.

...

And, I managed to test-wire a full Caravan setup. Two window regs, two pop-out window regs, two lock solenoids, and all the matching switchware and illuminated buttons. The regulators have over-current protection in them so they overload gracefully. And, some of the circuitry on the window switch bank does the automatic roll-down. That was a pleasant surprise, I was expecting that to be handled by some brain circuitry somewhere.

Hopefully soon I'll finish working on other people's cars and go back to working on my own before the summer's up.
 

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Detritus Maximus
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Can you use Mazak? As I recall, things like Hot Wheels, Tootsietoys, and carburetors were made of Mazak (or was it Zamak?). You know, like old decrepit Solex carbs....
 

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Discussion Starter #195
Can you use Mazak? (or was it Zamak?). You know, like old decrepit Solex carbs....
Yes. My plan is to use Zamak, which is an acronym for the metals in German. "Zinc, Aluminum, Magnesium, Kupfer (copper)"

I don't fault you for not reading any of the above posts in detail, but yeah, yes, my plan is to use Zamak, which is almost as strong as cast iron, and much stronger than aluminum, which should itself be plenty strong enough. I just have a problem getting enough. I wish I knew what car parts to grab that would be zamak, and proper alloys of zamak, not just zinc with some pot metal thrown in to bulk it up.

One of the reasons old Zinc/Zamak castings die, and irregularly so, is something called "Zinc Pest". The metal just randomly dissolves and disappears. We now know that zinc pest is the result of trace elements of lead in the alloy. A few decades later, somehow it just starts to eat itself. And what did they used to add to fuel? I can see why the carbs would rot and die.
 

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But I did read...that is why I asked. Your mentioning Zamak reminded me of Mazak, which I knew about from diecast toys. I looked up both and found the difference between the two, Mazak being slightly less pure, but more prone to the lead rot.
Not sure which is used for carbs, but I thought if you could use either alloy, old carbs would be a good way to get a bunch of material without robbing some poor kids toy box....
 

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Discussion Starter #197
I looked up both and found the difference between the two, Mazak being slightly less pure, but more prone to the lead rot.
Ahh, gotcha.

I thought if you could use either alloy, old carbs would be a good way to get a bunch of material without robbing some poor kids toy box....
Stop following me! Those kids never played with them anyways.

Actually I've been robbing the electrician's spare conduit coupler box. It's a matter of convenience, company pays for them, but sometimes it's nice to have extras on hand to make the job complete smoother, so old teardown bits go into a box. Well, I harvested all I could get from it. Still maybe just barely enough.
 

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I had a brake booster, I disassembled it, but I couldn't figure out how to unbolt the large black vacuum fitting. It has a hexagonal based to it, so obviously it's to be threaded and unthreaded, right?

Wait, no? Oops. It's not suppose to be loose from being spun? Well now I'm not sure it'll hold a vacuum.

Keith pulled a vacuum on it for me and said it held, but he was skeptical of it.

I might try to glob silicone around it to seal it.
NO! No silicone!

Just pull it out (Yeah I know, that's what She said!). See here for more information:


Dieter
 
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