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Rhyno
Mar 22, 2003

Psst! It's me!
The Sinister with the mutant gene.


grover posted:

A few 99-cent concrete blocks do wonders for adjusting jack height, FYI.

You and your mod-logic are not welcome here! This is the TOOL thread! Not the masonry thread!

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InitialDave
Jun 14, 2007

I Want To Believe.


Rhyno posted:

You and your mod-logic are not welcome here! This is the TOOL thread! Not the masonry thread!
Masonic Logic?

mod sassinator
Dec 13, 2006



Isn't there a danger the cinder blocks could fracture and collapse?

oxbrain
Aug 18, 2005

Put a glide in your stride and a dip in your hip and come on up to the mothership.


mod sassinator posted:

Isn't there a danger the cinder blocks could fracture and collapse?

Yes. Concrete doesn't bend or creak before failure, so it tends to be a surprise when your camaro drops on your mulleted head.

Brigdh
Nov 23, 2007

That's not an oil leak. That's the automatic oil change and chassis protection feature.


Theres also a danger that your jack stands could fail as well. Cinderblocks take a shitton of pressure to crush though. Just keep them upright like they should be

Paul Boz_
Dec 21, 2003

Sin City


Brigdh posted:

Theres also a danger that your jack stands could fail as well. Cinderblocks take a shitton of pressure to crush though. Just keep them upright like they should be

Uhhhh the fail point of a cinder block is much higher than that of a solid steel jack stand. A brick is just some loose particulate stuck together and cooked. When I was in high school one of my football teammate's dads collapsed a lung when his dumb rear end used solid cinderblocks for jackstands.

MonkeyNutZ
Dec 26, 2008

"A cave isn't gonna cut it, we're going to have to use Beebo"


Please, please never use cinderblocks to hold anything in the air that may have any body part under it. Ever.

Brigdh
Nov 23, 2007

That's not an oil leak. That's the automatic oil change and chassis protection feature.


I'd honestly be more worried about this:
http://www.ezcarlift.com/

basically an oversized scissors jack with no mechanical stops on little plastic caps

using a couple of cinderbocks with the proper caps to spread the load to boost up the jack is fairly safe, all things considered.

SNiPER_Magnum
Jan 21, 2001

Don't close. Don't close.

Nap Ghost

Lowes cuts wood for cheap, or free if the employees care very little.

InitialDave
Jun 14, 2007

I Want To Believe.


Wood can be fine, but you want big, solid lumps of it, a shape that's naturally stable, and pay attention to which way the grain's running. A stack of small pieces is still a really, really bad idea. An old railway sleeper makes a good way of raising a trolley jack another 6", but you have to make sure it can't move. One danger is that the concentrated load of the wheels can compress the wood, and if that happens unevenly, the whole thing will start to tilt over.

The issue with cinder blocks and bricks is that, while they are quite strong in compression, this is based on them being part of a wall, and evenly loaded. Again, if you put something like a jack on a cinder block, or stick it under an axle, you're then putting a hefty point load onto it - it might just crush a little bit, or it might crack, or explode into a small pile of rubble. If you put a steel plate or something on it first, it might be ok, but I wouldn't bank on it.

Also, the compressive strength of a brick might be as low as 3.5MPa. Steel? Hundreds of MPa. Four figures for some grades.

The point is, a jack, an axle stand, a hoist or whatever is a piece of lifting equipment. It is designed, tested and rated to lift and/or support a given load, usually with a safety factor of 4:1 or higher. Do not use anything else unless you know exactly what you're doing, and "I've been doing this for years" or "Someone on the internet said" does not cut it.

If you find yourself not having enough height on your trolley jack or stands, you should probably just get a bigger one. I use a long-chassis 2-tonne trolley jack, which will lift from 5.5" to 32" - my cheapo basic one might drop slightly lower (about 5"), but the 15" max height was a joke on some of my cars - wouldn't even touch the jacking point in the first place.

grover
Jan 23, 2002

PEW PEW PEW







mod sassinator posted:

Isn't there a danger the cinder blocks could fracture and collapse?
There's a danger your jack could fail, too. Nobody should ever be under a car held up by jacks, concrete blocks or not.

Hollow blocks are horribly unsafe for this, especially when laid on their side as people are apt to do, I don't think there's any question of that. Fortunately, solid concrete blocks are readily available and are much stronger for this. I use solid 4" cap blocks when I need a little extra lift height.

grover fucked around with this message at 14:46 on Jan 1, 2011

CatBus
May 12, 2001

Who wants a mustache ride?

As an update, I just got back from Harbor Freight. For some reason, they DID take 25% off the sale price of the jack stands (sale price was $44, marked down from $55), so they ended up $33 per pair, which is pretty good. I'm psyched to have decent clearance next time I'm rolling around under my vehicles

As a related note, jack stands easily act as point loads, and it is a bad idea to place them on an unconstrained concrete surface (like a block not contained in a form), holes or no holes. Stacking items to support a vehicle is bad practice, in general, anyway.

CatBus fucked around with this message at 16:57 on Jan 1, 2011

Aeka 2.0
Nov 16, 2000

Have you seen my apex seals? I seem to have lost them.






Dinosaur Gum

Brigdh posted:

I'd honestly be more worried about this:
http://www.ezcarlift.com/

basically an oversized scissors jack with no mechanical stops on little plastic caps

using a couple of cinderbocks with the proper caps to spread the load to boost up the jack is fairly safe, all things considered.

For the price you could get a real lift, used, shops are unloading lifts like crazy.
But the main issue is having enough space and making sure your concrete is thick enough.

Aeka 2.0 fucked around with this message at 18:37 on Jan 1, 2011

Suniikaa
Jul 4, 2004

Johnny Walker Wisdom

That's provided you get a good lift that isn't overrated

http://www.youtube.com/watch?v=XLUjq6ijvVc

Brigdh
Nov 23, 2007

That's not an oil leak. That's the automatic oil change and chassis protection feature.


Aeka 2.0 posted:

For the price you could get a real lift, used, shops are unloading lifts like crazy.
But the main issue is having enough space and making sure your concrete is thick enough.

I would love to have a real lift, unfortunately I rent a 1 car garage, and the concrete doesn't look that great. hydrolic scissors lifts don't provide enough access, and the thing I pointed out doesn't have any kind of locking mechanism that I can discern.

I need to buy a house with a decent garage or something.

ExtremeODD
Jul 16, 2005


When ever Ive used cinder blocks in the past I would put 2-3 pieces of dunnage between the block and car. Dunnage is the wood that comes strapped to the underside of bundles of bulk wood. You can get them free at Lowe's or Home Depot if you ask the lumber people nicely. I still keep the jack there as backup along with more than one backup incase stuff fails. Such as if you take the wheel off, put it under the car. Something to keep it from dropping all the way to the ground.

I have a few old tires I use for this purpose too, lay the wheel/tire down, throw old tire ontop. Ive fully lowered a crapbox civic on a stack like that and it was solid. I will say I never went under it.

oxbrain
Aug 18, 2005

Put a glide in your stride and a dip in your hip and come on up to the mothership.


Brigdh posted:

the thing I pointed out doesn't have any kind of locking mechanism that I can discern.

It's a screw jack, it IS the locking mechanism.

Brigdh
Nov 23, 2007

That's not an oil leak. That's the automatic oil change and chassis protection feature.


oxbrain posted:

It's a screw jack, it IS the locking mechanism.

My engineering professors would have disagreed.

Brigdh
Nov 23, 2007

That's not an oil leak. That's the automatic oil change and chassis protection feature.


What is a good tool/product for getting baked on oil off an aluminum engine block in tight spaces?

Sockington
Jul 26, 2003


Brigdh posted:

What is a good tool/product for getting baked on oil off an aluminum engine block in tight spaces?

Easy Off and a toothbrush? Make sure to flush thoroughly as it can gently caress with aluminium if it sits too long.

mod sassinator
Dec 13, 2006



There's also an aluminum safe version of simple green that might work well: http://www.simplegreen.com/products_extreme_motor.php

FatCow
Apr 22, 2002
I MAP THE FUCK OUT OF PEOPLE


Jared592 posted:

People Plasti-dipping all kinds of stuff these days:
Plasti-dipped wheels
Plasti-dipped car

The cool part is the way it's:
A: Removable
and
B: Paintable

You can have bright orange wheels on Monday and be back to stock on Tuesday.

This is getting done to my track car once it gets warm enough to paint outside.

oxbrain
Aug 18, 2005

Put a glide in your stride and a dip in your hip and come on up to the mothership.


Brigdh posted:

My engineering professors would have disagreed.

Did you drop out before friction 101?

Lyesh
Apr 9, 2003



oxbrain posted:

Did you drop out before friction 101?

Friction is easy enough to reduce that I'm not about to trust my life to something that relies on it. Not to mention the possibility of the screw mechanism itself failing catastrophically.

IOwnCalculus
Apr 2, 2003





I'm inclined to agree. There's a big difference between getting under something with only a jack supporting it, and something with stands / some equivalent supporting it.

It really is just an overgrown scissor jack. While I really like the idea and the usefulness of it, I wouldn't get under a car held up by a scissor jack, and I wouldn't get under that either...and using it to put your car on stands is overkill compared to a regular hydraulic jack.

SNiPER_Magnum
Jan 21, 2001

Don't close. Don't close.

Nap Ghost

I thought something like that would be cool for changing wheels and brakes at the track, but for $1600 hell no. And the paddock can be grass and gravel too, and I'll bet it's useless in that.

oxbrain
Aug 18, 2005

Put a glide in your stride and a dip in your hip and come on up to the mothership.


A screw jack will not suddenly rotate and drop. There is far too much friction, and no lubricant known to man will change that. The only way it's going to suddenly drop is if you strip off every last bit of threading, which would require far more weight than it would have lifted in the first place. It's basically a big bolt and nut, and you're constantly trusting your life to those.

Getting under a car on a scissors jack is dumb because it's narrow and might tip, and because scissors jacks are generally made of poo poo materials.

DJ Commie
Feb 29, 2004

Stupid drivers always breaking car, Gronk fix car...


Torsen differentials wouldn't work if worm/screw drive could spin itself the other way.

Nerobro
Nov 4, 2005

Rider now with 100% more titanium!


Baby Hitler posted:

Torsen differentials wouldn't work if worm/screw drive could spin itself the other way.

while this is true, the pressure angle is what matters. Torsen diffs are setup with the pressure angle almost 90 deg off from what you'd find on a screw jack.

If screws didn't self lock, screws would just fall out of everything.

Skyssx
Feb 2, 2001

by T. Fine


This very forum has pictures of a new (unused) GM scissor jack failing catastrophically by stripping every thread on the screw. It's a horrible design for a lift.

InitialDave
Jun 14, 2007

I Want To Believe.


While a leadscrew isn't that likely to back itself out (as Nerobo pointed out, applications where this is desired use a much higher helix angle), you do still have to worry about it stripping. And even if it's perfect when new, over time you can get wear in the components.

I had an issue with clamp on a cut-off saw at one place I worked where it just wouldn't tighten down on the workpiece properly - turned out that debris had been working its way into the screw thread over time, and while the thread itself was perfectly fine (hardened steel), the block it ran in (bronze, I believe) had been worn almost completely smooth in just a few years of use. It'd screw down, but anything more than the lightest resistance would cause it to skip and back off. From the outside, you couldn't see anything wrong with it.

Now, that's a fairly extreme example, and it's not likely to happen with an occasionally-used jack, but stuff like this can go wrong. And, as Skyssx pointed out, the jack might well be poo poo in the first place. Most leadscrews are ok, but if you don't look after them (grease the threads etc), you might end up dropping a car on your head. Or bring down an aircraft.

Jared592
Jan 23, 2003
JARED NUMBERS: BACK IN ACTION


FatCow posted:

This is getting done to my track car once it gets warm enough to paint outside.

Post a thread when you do please, as I think it'll encourage a lot of others to do so more than my post buried in the Tools! thread.

Vin BioEthanol
Jan 18, 2002

by Ralp


Anyone ever use the harbor freight plastic welding kit?

http://www.harborfreight.com/plasti...102&tag=froogle

Not car related but the plastic housing/frame inside my gas range that holds the circuit board and control panel just snapped the other day when the off button was pushed with the front face of the control panel caving in. All the boards are fine, just this frame/housing thing that's broke. I can't buy it by itself, have to buy the whole assy boards and everything for like $100.

What I'm talking about is basically just like a plastic car-stereo mounting kit. Picture one of those that's broke on the top and bottom horizontal rails. (this plastic frame is hidden behind some metal a "backguard" with only the button face overlay showing, so I can ugly it up a bit with no cares)

Wondering if anyone's used this and if it's any good for repairing stuff like this.

Is there some kinda of glue that I could use and jig up with some c clamps that would work better?

It is going to have to handle a little bit of pressure from butan-mashing.

Vin BioEthanol fucked around with this message at 16:35 on Jan 5, 2011

Jared592
Jan 23, 2003
JARED NUMBERS: BACK IN ACTION


I'd imagine you could probably do that with just some 2-part epoxy made for plastic. Home Depot or Lowes'll have that.

Vin BioEthanol
Jan 18, 2002

by Ralp


Thanks, I don't know why I didn't think of that. Probably cause it's been years since I've used any epoxy on anything and maybe partly cause I keep seeing the plastic-welding kit in the ads and it's like a tool looking for a reason for me to buy buy buy!

Geoj
May 28, 2008

BITTER POOR PERSON


If you use epoxy just make sure you get high-quality stuff, generally speaking the longer the cure time the stronger its going to be after setting up. Avoid anything that has a "5 minute working time/20 minute cure time" or similar.

mod sassinator
Dec 13, 2006



If it's just holding a circuit board or something small you might even try super glue. It works great on plastic.

Vin BioEthanol
Jan 18, 2002

by Ralp


mod sassinator posted:

If it's just holding a circuit board or something small you might even try super glue. It works great on plastic.

I would normally, use that poo poo on everything including myself but this also has to hold the thing in place with hungry people on the other side pushing on the membrane buttons.

sharkytm
Oct 9, 2003

Gimme Gimme Swedish Fish...



Fallen Rib

I've used the plastic welding kit. It works, but isn't very good. I've used larger ones, and they work MUCH better. For something like you are taking about, I'd use epoxy and some steel reinforcement pieces. Drill the steel, and let the epoxy flow through it, making a "rivet" out of the epoxy. We use it a lot on fishing boats to hold fluxgate compasses and autopilot rudder feedback arms. Works fine.

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Brigdh
Nov 23, 2007

That's not an oil leak. That's the automatic oil change and chassis protection feature.


Where do I find a spanner or monkey wrench for a 52mm nut? No one in town has anything close

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