Thread: Dawn Disaster

Originally Posted by CMB

Don't mean to hijack the thread but couldn't let this comment slip through the cracks. (no pun intended re thread topic).

How is the doctor supposed to pay his admin staff?...overheads for facilities?...massive insurance premiums?...and be reimbursed for the hours put in staying on top of the latest medical breakthroughs in order to provide us with the best possible care (outside of consulting hours)?

I ring an hour before my appointment times to see if they are tracking on time.

Craig.

This is actually a very valid point. The overhead costs are massive, in fact I know of one GP who has stopped performing vasectomies purely because of the massive increase to his insurance premium to cover this simple procedure.

Originally Posted by DSEL74

What I was curious about though is the cost variance between brazing and arc aside from labour and commercial costs.

Ball park, off the top of my head, there would probably be say $10 worth of Low Hydrogen electrodes used plus maybe $5 worth of gas to preheat with, (you wouldn't necessarily need to use oxy acetylene for this either), against probably $30-40 worth of Gas and Brazing consumables.
Remember though, that the Low Hydrogen method for cast iron does not suit all applications despite its cost advantages and there are times where Brazing is the weapon of choice. This is where experience and knowledge enters the equation.

G'day DSEL,
I have done a few cast iron repairs using TIG and stainless filler, a technique I tried as an alternative to bronze welding.
I'm not going to declare if this is a recommended repair process or not and I wouldn't do it on a critical part without the advice of an expert but all I can say is that it has worked for me to date including repairs to a couple of vices which are still going strong.
I do the usual pre & post heating in the gas barbie and if necessary for cosmetic reasons grind the repair back.
I use stainless filler because of the nickel content (cast electrodes are pretty much pure nickel) but normal MS filler rods might work too, I just havent tried it yet.
I'm not sure where you are in Melbourne but I'm in the northern suburbs (Fawkner) and if you like I'd be happy to have a crack at fixing this one for you. (no pun intended )
Cheers,
Greg.

Originally Posted by kwijibo99

G'day DSEL,
I have done a few cast iron repairs using TIG and stainless filler, a technique I tried as an alternative to bronze welding.
I'm not going to declare if this is a recommended repair process or not and I wouldn't do it on a critical part without the advice of an expert but all I can say is that it has worked for me to date including repairs to a couple of vices which are still going strong.
I do the usual pre & post heating in the gas barbie and if necessary for cosmetic reasons grind the repair back.
I use stainless filler because of the nickel content (cast electrodes are pretty much pure nickel) but normal MS filler rods might work too, I just havent tried it yet.
I'm not sure where you are in Melbourne but I'm in the northern suburbs (Fawkner) and if you like I'd be happy to have a crack at fixing this one for you. (no pun intended )
Cheers,
Greg.

You can also get cast iron filler material for the tig process. I haven't personally used it, but it is out there. No idea of pricing etc though.

Looks like you guys were right on further investigation after I have calmed down, the crack seemed to have surface rust on 90% and only a small clean section. So I guess I only finished it off rather than being the cause. it is still disappointing that it was damaged at all.
Break_3896.jpg



Gave the table shaft a bit of a clean I thought there was a lot of rust scale on it, but it now looks more like the shaft is cast also?? The texture is not pitted but rather raised and the points where the mounts and table have been are worn smooth.

Shaft_3911.jpg

Originally Posted by DSEL74

Gave the table shaft a bit of a clean I thought there was a lot of rust scale on it, but it now looks more like the shaft is cast also?? The texture is not pitted but rather raised and the points where the mounts and table have been are worn smooth.

Shaft_3911.jpg

hey,

Obviously it is hard to see from a photo, but I am thinking that you may still have some scale build up on the bar, I have seen something similar before when using electrolysis on some really rusted parts (the smooth area looks like what I would expect to see behind the casting areas, the rust doesn't generally seem to get to these parts much). If you haven't tried already, if you use a brass wire wheel on an angle grinder, like this:

image.jpg
Not the steel wheels (they will scratch the steel), it should come off. If you have tried the wire wheel, or you are using a drill and not a grinder (I started with the drill press and it is hopeless for this job, the grinder is defiantly the tool), try holding it for a few seconds with a bit of pressure, the more I look at the photo the first bar really looks like what I am talking about, I got tricked the first time, and it wasn't until I had another go at it that I realised what I thought was pitting was coming off, and then I looked closer and realised it was raised and not pitted.
The advantage is, if I am correct the end result will probably be smoother than what you currently have.

Cheers,

camo

Originally Posted by Pete F

If you then give it a coat of flat black paint it should hide the bronzing and will be a reasonable job aesthetically.

Originally Posted by 2blast67

What Pete says in the above is on the money with brazing and painting.

Not quite. A coat of red paint would be more appropriate for a Dawn post drill.

Joes 61124c.jpg

A picture of jhovel's Dawn 611 (which is in better nick than mine).

Cheers, Vann.

Originally Posted by Vann

Not quite. A coat of red paint would be more appropriate for a Dawn post drill.

Joes 61124c.jpg

A picture of jhovel's Dawn 611 (which is in better nick than mine).

Cheers, Vann.

Actually the paint on this one is black, and there is nothing underneath so it was either stripped to bare metal and done in black or it is original.
Although it may not be paint it is a very hard thin coating bit like case hardening, but comes off with heavy wire brushing. It doesn't look to me to be a blackened rust layer but thin paint under all the muck and rust.

I am really curious about this ones origins as it has a number of variations to any of the others I have seen.

Originally Posted by DSEL74

Although it may not be paint it is a very hard thin coating bit like case hardening, but comes off with heavy wire brushing. It doesn't look to me to be a blackened rust layer but thin paint under all the muck and rust.

Yep,

thats the stuff I was referring to in my earlier post, not sure if you missed it.

cheers,

camo

Originally Posted by camoz

Yep,

thats the stuff I was referring to in my earlier post, not sure if you missed it.

cheers,

camo

I think we have crossed wires here, Earlier I was talking about the table post and had photos, you responded after that. More recently I was talking about the main casting which usually painted red, mine is black.

Originally Posted by DSEL74

I think we have crossed wires here, Earlier I was talking about the table post and had photos, you responded after that. More recently I was talking about the main casting which usually painted red, mine is black.

My mistake, it appears I am the one not following along, I was wondering why you would be thinking the bars had been painted, although i must say the way you are describing it, it sounds exactly like what I have experienced before (initially it looks like it won't come off with a pass Witt the angle grinder with wire brush, and then when you hit it for a few more seconds it starts coming off), I have noticed it on metal bar with more than surface rust, and cast table tops.

cheers,

camo

IMG_3916.jpgIMG_3917.jpgIMG_3941.jpgIMG_3942.jpgIMG_3943.jpg

Casting all welded up thanks to one of the forums members assistance. Thanks Matty.
Thanks to all the other members that graciously offered to do it for me also.

Matty & I had a combined go at getting the main gear and the shaft free. Heating, liberal amounts penetrene, more heat, a lot of leverage, and a few taps, and she didn't ene give a mm.

Frozen solid!!!!

Originally Posted by camoz

My mistake, it appears I am the one not following along, I was wondering why you would be thinking the bars had been painted, although i must say the way you are describing it, it sounds exactly like what I have experienced before (initially it looks like it won't come off with a pass Witt the angle grinder with wire brush, and then when you hit it for a few more seconds it starts coming off), I have noticed it on metal bar with more than surface rust, and cast table tops.

cheers,

camo

With a run on the 8" grinder & wire wheel then a light sand in the lathe it has cleaned up but is still pitted in sections. I can live with it in the condition it's in. Can't look like new, needs a little life to show in it.

IMG_3937.jpgIMG_3938.jpgIMG_3939.jpgIMG_3940.jpg

Ok here are the parts that were soaked in the 9:1 molasses solution after one week. They have been washed and scrubbed with a brush.
Molasses1.jpgMolasses2.jpgMolasses3.jpg


Decided to try a wire wheel and wire brush on parts to see if if affects the process.

Partial brushing on the lever arm and cog

Wired Wheeled01.jpgWired Wheeled02.jpgWired Wheeled03.jpgWired Wheeled04.jpgWired Wheeled05.jpgWired Wheeled06.jpg



Fully wire brushed

Wired Wheeled07.jpgWired Wheeled08.jpgWired Wheeled09.jpgWired Wheeled10.jpg


Back in the molasses, 1 week wasn't expected to se much result usually say about a month.