Granite Plate

[Dabbler]

@L98Fiero Fastenal doesn't carry it any more. I bought their last 2 tubes 4 years ago.

I have an account. but I won't be ordering from them ever again. I have contact with the Western Canadian Sales manager, and the simply don't want to do business with accounts less than 10K$ per year. I think they are supremely stupid for this decision.

 

[Tom O]

I took it out of the box then I used the box to cover and protect it.

 

[phaxtris]

You can often get it auto parts suppliers, as Prussian blue is also used for gear marking compound when setting up differentials

 

[Tom O]

I see some people that are using the red coloured one for scraping is there a difference between the two or is it to make the hands look cleaner?

 

[Dabbler]

@Tom O Red spotting paste is used the same a blue: nowadays the particle size is similar.

This is opposed to the now-more-popular water based yellow, red and blue coatings. They contain far less dye and are less opaque. They are great for getting near the target - say 5 tenths (perhaps a little less?). If you are going for sub-tenths, then Prussian Blue seems opaque enough to see the high spots.

I haven't heard that anything else comes close, but with new technology, it is always possible.

 

[phaxtris]

In regard to the opacity of the Prussian blue

I don't know if this trick works for scraping, but when using blue or the yellow gear marking compound for setting up diff's, a lot of guys thin it out with a touch of gear oil to make the pattern easier to read, maybe it would work for this purpose as well ?

 

[Dabbler]

If you use a brayer on a surface plate, little or no thinning is required.

If you are thinning it out -on a surface plate, it is because it has been applied a little thickly. The coating, to be optimal, should be about a half-tenth thick. If thinned the imprint is very faint (my friend Bert showed me this with Prussian Blue and Varsol).

Gears are another matter - and I'm not that guy.

 

[PeterT]

What is the recommended cleaning solvent for Prussian blue (that wont create issues for the granite surface)

 

[DPittman]

What is the recommended cleaning solvent for Prussian blue (that wont create issues for the granite surface)

Is there any solvent that could damage a granite surface plate?

 

[PeterT]

Not sure about damage, granite porosity & permeability must every low. Staining or partial penetration maybe? Or adversely affecting another application of blue? For example some thinners have more of a light oily content than others, lacquer thinner & kerosene feel that way to me. Vs. methanol, acetone, alcohol... more light end stuff. From memory, Prussian blue has some kind of viscous oil base but I just remember it didn't come off my fingers very quick LOL.

Sounds like the trick is don't leave the blue on for extended period to begin with.

How I got old prussian blue out of surface plate

Well- I got most of it... Have a pink surface plate and used prussian blue on one part- and with various interruptions ended up putting on several layers which sat for some time. I went to wipe it off with lighter fluid- and got some- but not all. I then tried laquer solvent and it got a...

www.practicalmachinist.com

 

[Dabbler]

What is the recommended cleaning solvent for Prussian blue (that wont create issues for the granite surface)

Never use anything oil based near a surface plate, including petroleum distillates such as Varsol.

I use a big box of Clorox ammoniated wipes for all surface plate cleaning, and have for 40 years.

 

[DPittman]

I have no experience with a surface plate but have had lots of Prussian blue over my hands and everywhere else it seems. I have an ancient tube of it that always seems to leak a bit.

If I did have a surface plate and had to remove Prussian blue off that simpler methods did not work well with, I would use carb cleaner. I see one of the posters in that practicalmachinist thread suggested using brake cleaner. Brake cleaner works pretty good on a lot of stuff but when it doesn't come off with brake cleaner I am almost always successful with carb cleaner.

 

[PeterT]

Never use anything oil based near a surface plate, including petroleum distillates such as Varsol.

I use a big box of Clorox ammoniated wipes for all surface plate cleaning, and have for 40 years.

Those wipes remove prussian blue?

 

[Tecnico]

Hey I've got a blue scribe just like that one on the left. No brand name on mine and pretty basic. I use mine for setting lathe tool height.

I could have written this ^ post word for word!

Mine came from Busy Bee.

D

 

[DPittman]

I could have written this ^ post word for word!

Mine came from Busy Bee.

D

I got mine second hand but if I recall correctly I think it had an old "craftsman" sticker/label on it? It is almost for sure older than Busy Bee?

 

[Dabbler]

Those wipes remove prussian blue?

Unless they've removed the ammonia, it cuts the binder/carrier.

The prussian blue carrier seems like an oil or grease, but if it were, it would do 'bad things' to the granite. I have been warned by more than one T&D maker to keep all oils and greases away from my surface plate. It seems bad for the structure of the granite, somehow.

this is hearsay, It has worked well for me.

-- but I haven't 'blued up' anything in about 6 years now....

 

[Susquatch]

It looks like Dykem (a manufacturer name) also makes a high spot / Prussian blue in addition to layout blue.

Finally! An answer to a riddle that has been pestering the daylights out of me.

I've been using some old Dykem with no problems for a thousand years. Then I ran out. The last can I got was crap! Waaaaaay too thick for testing fits, clearances, and interferences, etc. Got some Prussian Blue on amazon that worked fine.

Now I know why the Dykem was foobarred. Thanks @PeterT !

 

[Susquatch]

@L98Fiero Fastenal doesn't carry it any more. I bought their last 2 tubes 4 years ago.

I have an account. but I won't be ordering from them ever again. I have contact with the Western Canadian Sales manager, and the simply don't want to do business with accounts less than 10K$ per year. I think they are supremely stupid for this decision.

I hope that doesn't happen here. The local Fastenal store is still good to me. They prefer to sell me a box of screws but will even sell me 1 screw if I am willing to wait for them to ship it in. Your outlets policy sounds like a path to bankruptcy if you ask me.

 

[Susquatch]

I could have written this ^ post word for word!

Mine came from Busy Bee.

D

@DPittman & @Tecnico

You two guys need to make yourself a lathe height standard. You will NEVER regret it.

I usually recommend making one as the first project for any new lathe owner. Both of you have been around a lathe for a while now so I'm surprised you don't already have one. It's time.....

Lots of different designs out there. I made mine from a 1" diameter bolt. Some guys like to put a magnet in the head. I never did that and don't miss it. KISS.

Lots of guys on here have made one. Just google "lathe height standard" and pick your favorite design.

 

[DPittman]

@DPittman & @Tecnico

You two guys need to make yourself a lathe height standard. You will NEVER regret it.

I usually recommend making one as the first project for any new lathe owner. Both of you have been around a lathe for a while now so I'm surprised you don't already have one. It's time.....

Lots of different designs out there. I made mine from a 1" diameter bolt. Some guys like to put a magnet in the head. I never did that and don't miss it. KISS.

Lots of guys on here have made one. Just google "lathe height standard" and pick your favorite design.

I actually had made one but I prefer the height gauge stand.