Welcome aboard Onterrible !
Alpinord tipped me off about this thread and since I had bored him to death on the subject a year ago, I thought I would do the same to you!
I did a series of experiments on the melting of the various clear base repair materials I bought from Slidewright 2 seasons ago.
I hooked up the Pro Fix iron to a variable voltage supply and measured the tip temperature as a function of applied voltage. I assumed that at regular Outlet voltage (I measured mine to be 122V) the full power of the Iron was 40W as indicated on the label and I further assumed that the iron was completely resistive so that the power is given by V^2/R and hence calculated the power that the iron was producing. I measured the tip temperature by pressing a thermocouple onto the center of the tip. I got repeatability of about +/- 5oC so that’s good enough in my book.
When the tip temperature had stabilized I ‘Bonded’ one of three materials (Metal Grip LK20902M, Weld Ribbon K512W, Weld Wire KW341) onto the surface of a Mirror (I knew it wouldn’t stick to the mirror) and when the blob had cooled I lifted the blob off to photograph.. After each material I ‘Cleaned’ the tip of the iron by wiping it on a piece of particle board. All samples are shown in attached table. If you click on the image it should enlarge enough for you to read the numbers. All temps are in centigrade.
- All materials are basically not usable at tip temperatures less than about 180 C
- Metal grip seems to flow and be usable at tip temperatures from 180 C to 300 C
- At 300 C Metal Grip starts to acquire a blue tint.
- Around 345 C Metal grip also has red streaks in it
- By 415C (full power on Pro Fix Iron) Metal grip had brown regions in it the cause of the discoloration in a base repair which originally started me on this track (See below )
- Ribbon seems to work well at temperatures from 250C upwards
- My observations supported a claim by Alpinord that Weldwire is a higher melting point material – I would say it is not useable below about 300C
- Optimum Temperature range for Metal grip is Probably 220-300C,unless discoloration is not a concern (e.g. in black bases where discoloration might not be noticeable or when you don’t care about the appearance of your bases, only their function)
- Weld Ribbon can be used at Temperatures from 250C to 400C
- Weld Wire needs Temperatures over 300C
- A single Fixed temperature iron is probably not satisfactory for all 3 materials
Well there you are. More than you ever wanted to know about metal Grip.
Based on this and some crude adhesion tests I did, my preferred method of fixing core shots is use metal grip and full temperature (415C) for best adhesion if the base is black. If you have a colored or white region & discoloration is a problem, use a layer of epoxy then fill with Weldwire or base repair ribbon (which I think is more durable)
I leave you to convert my centigrade to Farenheit.
Have fun !