simple Hi-Tek coating

[kevin c]

Coming to the US anytime soon?

[HI-TEK]

Well...
I'm loving the Bonded Mold release.
Treated and ran 125Conical molds today for 1 hr. 3000 bullets later and they were dropping like fly's.
Then treated and changed to 156RNFP for 1 hr. another 3000 bullets and dropping free, no worries.
As a final go. treated and ran 125gn SWC for 1 hr. 3000 of these were dropping out easy as...

Great stuff.
But... don't use it on the top of the sprue plates as it slows down the solidification of the sprue.

Great results.
I would suggest, to use the non bonding version for Sprue plates area as the bonded version does offer some insulation, and that is why it may slow down alloy chill rates at the top. The non bonded version has much less insulating property and should work OK there.
Non bonded version can be topped up, with brushing on the Sprue plate area, to stop build up of spatter. The bonded type release coated areas inside Moulds should not need topping up.

To Kevin C
You need to make contact with Alan Esterly. I think he may be having limited stocks in a few days, of both bonding and non bonding grades..
Again, first in best dressed.

[Tazza]

Well...
I'm lovin the Bonded Mold release.
Treated and ran 125Conical molds today for 1 hr. 3000 bullets later and they were dropping like flys.
Then treated and changed to 156RNFP for 1 hr. another 3000 bullets and dropping free, no worries.
As a final go. treated and ran 125gn SWC for 1 hr. 3000 of these were dropping out easy as...

Great stuff.
But... don't use it on the top of the sprue plates as it slows down the solidification of the sprue.

Looking forward to giving it a go in a week or two, it will be ideal for my recent mould haul that have some with mild pitting. The big test will be if it can prevent ir slow lead build up between the mould and sprue cutter.

You mention that it's not good on top of the cutter, i'll be sure to keep it to the under side. I wonder why it is making the lead solidify slower when on top of the sprue cutter.

[HI-TEK]

Looking forward to giving it a go in a week or two, it will be ideal for my recent mould haul that have some with mild pitting. The big test will be if it can prevent ir slow lead build up between the mould and sprue cutter.

You mention that it's not good on top of the cutter, I'll be sure to keep it to the under side. I wonder why it is making the lead solidify slower when on top of the sprue cutter.

Tazza
Read previous blog number 14262
The Bonding product has some insulating property, which seems to slow heat transfer rates to and from alloy.

From previous tests, using the non bonding 500+, simply brushed onto all internal areas, including into corrosion holes, that badly pitted Mould performed with perfection all day without re-application.
As suggested in blog number 14262, very sparingly, brush on the powdered non bonding version (500+) onto Sprue cutter surfaces.
Surfaces only need what can be described as a stain.

[Ausglock]

The big test will be if it can prevent ir slow lead build up between the mould and sprue cutter.

Zero lead smear on the mold top or the underside of the Sprueplate.

[HI-TEK]

[QUOTE=dikman;5 I occasionally had a bit of lead smearing but don't get any with the coating plus the sprue puddle drops clean from the sprue plate. Bit of a bonus that.

My guess is, that Lead smearing may be due to alloy not quite setting before Sprue cutter is slicing of the excess.
I suggest, may be wrongly, that alloy may be at higher temperatures to get adequate fill, and, in some automated systems, there may not be enough cooling taking place, so the cutter smears the molten alloy as a thin film.
With next batch, and also possibility of having varying alloy composition, that same casting temperature that caused smearing, actually works, as that newer batch of alloy may crystallize more quickly before Sprue cutter actuates. It may also be a contributing factor of ambient temperatures being cooler on days where alloy sets more quickly and there is no alloy smearing.

[HI-TEK]

Zero lead smear on the mold top or the underside of the Sprueplate.

I am suggesting/guessing, that you are casting at just barely adequate temperatures to get fast cooling & setting of poured alloy.
The cutter is slicing solid & set alloy, so there is no smearing taking place.
The release agent/s simply stops alloy, and spatter sticking to surfaces from the pour.

[HI-TEK]

.
Q1 The big test will be if it can prevent ir slow lead build up between the mould and sprue cutter.

You mention that it's not good on top of the cutter, i'll be sure to keep it to the under side.
Q2 I wonder why it is making the lead solidify slower when on top of the sprue cutter.

Eazza,
My suggestion to question 1 above, I suspect, that build up between Sprue Cutter and Mould starts with molten Lead smearing initially.
This is a thin later that seems to lift cutter, and allowing more thin alloy film to deposit on original film. As per my suggestions, the smear seems to be molten alloy.

My answer and suggestion is to Q2, that alloy on top is being cooled by air. Air is a poor conducted of heat.
If alloy is too hot, the excess will not set before Sprue cutter is actuated. Cutter in fact is smearing molten alloy. That smearing can be made worse if the alloy is too hot, and there is also an insulating agent preventing adequate cooling on the waste with the minimum surface contact by the excess.
I could be totally off the mark, but that is the way I see it.

[Ausglock]

I am suggesting/guessing, that you are casting at just barely adequate temperatures to get fast cooling & setting of poured alloy.
The cutter is slicing solid & set alloy, so there is no smearing taking place.
The release agent/s simply stops alloy, and spatter sticking to surfaces from the pour.

Nope. always cast at 710 Deg F.
Just gotta know your gear and how to work it.

[HI-TEK]

Nope. always cast at 710 Deg F.
Just gotta know your gear and how to work it.

I agree.
But is smearing, caused by the spreading of the molten alloy by cutter?
If alloy is set to a solid there should not be any smearing during cutting??? I don't know as I said, but it certainly looks that way to me.

I am referring to others that may be casting at different temperatures than what you use.

I recall commercial caster adding more cooling blowers to automated casters to try and set the poured alloy more quickly, as they were not as fussy with casting alloy temperatures, but wanted faster output and producing less faulty casts.

[Ausglock]

the hole in the sprueplate has to be sharp and the plate flat.

[HI-TEK]

the hole in the sprueplate has to be sharp and the plate flat.

That is 100% correct.
But I am thinking, if excess not set or cooled adequately, would the cutter be trying to cut a liquid.
Both the plate and cutter can be sharp, but how would this deal with a liquid partially set alloy?
Just wondering....

[Jatz357]

From tests I have completed using the 500+ the product is fantastic. I have a couple of moulds that don't like releasing one cavity and after treating with 500+ the problem reduced dramatically. I apply a thin dusting to the complete mould surface and sprue cutter and that also stops lead smearing in the vent lines if the mould gets a little hot. It's easy to apply and lasts quite a while.

Looking forward to testing the bonded version.

[Jatz357]

Also completed another infrared oven Hi-Tek bake test the other day.

This test was baking the coating without pre-heating the projectiles after allowing the coating to air dry.

1st coat was applied and ambient temperature was around 12 degrees C, projectiles were left to dry for about 90 minutes. After this time they were put on the conveyor. Starting temp of the projectiles was around 10 degrees C before baking. After bake and cool down they past the smash test with no problems.

2nd coat was allowed to air dry for just 20 minutes, ambient temp was about the same. They were run through the oven again and past the smash test.

From previous testing and discussion with Hi-Tek Joe it appears infrared cures the coating from the inside out and this may be why the coating can be baked without pre-heating. Pre-heating will remove / reduce any moisture, trapped moister will turn to steam and force the coating out of the lead pores and cause poor adhesion.

Conventional ovens and radiant heat will skin the coating and cure from outside in. This skinning affect can trap moisture.

More testing needs to be completed to confirm whether it is advisable to bake Hi-Tek using an infrared oven with limited drying time and no pre-heat. Ambient temperature, humidity and dew point may have an affect of final results too.

[Ausglock]

I have some Ceramic IR heating panels on the way.
I have a 900mm wide oven I'm going to gut and retrofit with the IR panels.
See if I can blow myself up...lol

[Tazza]

Jatz - I'm wondering if the added warming effect of when the cast enter the oven helps to dry them that last little bit if needed, as they don't just get whacked to 200c in one hit, they slowly get exposed to the IR heat so they warm up slower as they enter the oven, vs being thrown into a regular oven that is already heated to 200c. On a side note, boo on the cold weather, our mornings get to 8 or so c, but during the day mid 20s

Joe - i'm thinking the same for lead smear, as i'm currently using a master caster that holds only one mould, it gets hot, the fan does cool it, but possibly not enough to ensure the lead isn't solid enough to not leave residue on the sprue plate. Being a softer metal, i'm not 100% sure if the lead needs to be molted to transfer, it is softer so you can still get transfer, the hotter it is, the easier it will be. You are spot on about a little gets under there, allowing more to get under with additional pours.

I cast at quite low temperatures, about 330-340c depending on the blend i run, it's only 10-20c over the melting point of the blend. So quite cool in the scheme of things. If i cycle things slower to allow the mould to cool off more, i get bumps on the base where the sprue is cut off, even with new sharp sprue plates, it's just how my machine runs, i know it well, just as Trevor knows his machine. It's a trade off for me, clean sprue cutters or have bumps on the base of my cast. The non bonded 500+ did help, but it didn't stop it with how i run my machine, but it may help if i run it cooler and not get the bump, i have not tested it in this way yet, but it will make for a good experiment.

I just sold my last batch of 83kg of 180 grain .30 cals, so it's an excuse to get to casting more and testing the 500+

[dikman]

A timely discussion regarding the bonded version as I'm about to try it today. I've coated the mold but haven't cured it yet and after getting good results with the 500+ on the sprue plate I figured the bonded had to be better so coated the plate too. I'll clean the sprue plate and re-coat with 500+ after reading this.
As for the smearing what Joe says about the lead being too soft when cutting makes sense, at least in my case. A brass mold is worse for this because it's a bit like soldering when it gets too hot.

[Tazza]

A timely discussion regarding the bonded version as I'm about to try it today. I've coated the mold but haven't cured it yet and after getting good results with the 500+ on the sprue plate I figured the bonded had to be better so coated the plate too. I'll clean the sprue plate and re-coat with 500+ after reading this.
As for the smearing what Joe says about the lead being too soft when cutting makes sense, at least in my case. A brass mold is worse for this because it's a bit like soldering when it gets too hot.

That was my concern with brass moulds too, all mine are aluminium or steel/cast iron. It has always concerned me with how to remove it if it was to actually stick in a cavity

Looking forward to hearing how you go with your casting session.

[dikman]

No real problems, I cast 170 for the .38 and 170 of the .429. I still had a slight issue with one particular cavity in the brass mold but even when some didn't want to drop they were easy to dislodge. I'm not sure, though, if I have an even coating in a couple of the cavities.The other is a Lee 2-cavity which didn't give me any issues, I figure the larger heavier boolit helped.

I'm pretty pleased with the 500+ on the sprue plates. In the past I would occasionally have the puddle sticking in the pour holes of the sprue plate but I had no problems with either mold this time, the puddles dropped clean. Might be just co-incidence but I thought the boolits looked real nice and smooth.

I have a Lee 2-cavity for the .38, which I haven't used since getting the brass mold but I suppose I should give it a try sometime and see how that performs with the coating and smaller boolit.

I just wish I'd had this stuff before casting the thousands that I've already done.

[Tazza]

My lee 6 bangers when i used them, were hard to get the sprues to drop. I'd make sure i laid enough lead on them to join them all up, but i'd need to beat on them pretty hard to get them to release the long sprue.

I'd like to think the bigger the bullet, the more shrinkage you get to assist in letting them drop.