Post subject: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Sun Mar 04, 2018 2:12 am
Established Member
Joined: Sat Mar 03, 2018 1:59 pm Posts: 12
I am using a duel zone ba5t and zinc+ lap from gearloose and ive been noticing these strange clusters of material pop up. I think they are the PCD diamond stick residue but im not sure since im new to using this lap. see attached for a photo. Any help would be nice since I dont want to be damaging my lap.
Mod edit: removed original picture because it was way over 600px wide, replaced with resized one, click image below for fullsize view.
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Sun Mar 04, 2018 8:12 pm
Established Member
Joined: Sat Mar 03, 2018 1:59 pm Posts: 12
it seems to be coming from the inner (100k PCD stick) which on that lap is Ba5t. It seems to show up in clumps like the one you see on the towel. The stone im trying to polish is corundum
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Mon Mar 05, 2018 1:42 am
Moderator: Lapidary Diamonds
Joined: Mon Aug 20, 2012 11:32 pm Posts: 1747 Location: Florida, United States
Lucinator wrote:
it seems to be coming from the inner (100k PCD stick) which on that lap is Ba5t. It seems to show up in clumps like the one you see on the towel. The stone im trying to polish is corundum
Could it be some of the BA5T alloy that is breaking off and agglomerating as you polish?
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Mon Mar 05, 2018 10:30 am
Gold Member
Joined: Thu May 12, 2016 2:18 am Posts: 1542
I have seen this myself when I had a BAT lap that had some differences in hardness in the lap. It seems that the alloys were not well mixed when the lap was cast. The difference in hardness caused skipping and gouging when polishing. I sent it back to Gearloose, he agreed with the problem and promptly replaced it. Great service as always!
However, it is more likely that the lap is not properly charged and/or lubricated . Whenever you see metal sloughing off on a stone you are trying to polish, this is the usual cause. Of course, this assumes that the facet surface is properly aligned to be flat with the lap. A misaligned facet can gouge the lap creating metal shavings.
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Mon Mar 05, 2018 8:09 pm
Established Member
Joined: Sat Mar 03, 2018 1:59 pm Posts: 12
1bwana1 wrote:
I have seen this myself when I had a BAT lap that had some differences in hardness in the lap. It seems that the alloys were not well mixed when the lap was cast. The difference in hardness caused skipping and gouging when polishing. I sent it back to Gearloose, he agreed with the problem and promptly replaced it. Great service as always!
However, it is more likely that the lap is not properly charged and/or lubricated . Whenever you see metal sloughing off on a stone you are trying to polish, this is the usual cause. Of course, this assumes that the facet surface is properly aligned to be flat with the lap. A misaligned facet can gouge the lap creating metal shavings.
Steve
when you had the problem with the lap did you see gouging in the lap, since as far as i can tell I cant see any damage, just the material?
Also here is how I charged it, spread small amounts of PCD diamond stick on the inner part of the lap, used a old credit card to spread it out slightly and then used a corundum boule while having the lap rotate slowly (<100 rpm). If im doing it wrong plz let me know.
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Mon Mar 05, 2018 11:44 pm
Moderator: Lapidary Diamonds
Joined: Mon Aug 20, 2012 11:32 pm Posts: 1747 Location: Florida, United States
Lucinator wrote:
Also here is how I charged it, spread small amounts of PCD diamond stick on the inner part of the lap, used a old credit card to spread it out slightly and then used a corundum boule while having the lap rotate slowly (<100 rpm). If im doing it wrong plz let me know.
The PCD diamond is so small and the BA5T or BATT surface is soft enough to accept the diamond particles without pushing those particles in with a sapphire boule. Just spread the PCD compound on the lap surface and add oil or water. So, ditch the boule for polishing compound. It could most certainly shave off metal alloy which you then observe.
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Tue Mar 06, 2018 9:11 pm
Established Member
Joined: Sat Mar 03, 2018 1:59 pm Posts: 12
tried using the lap like you said. I first wiped the lap clean, then applied PCD 100k diamond stick to the inner part of the lap. Unfortunately I again started to see the same silvery stuff again. Unless im doing something wrong that I'm not aware of then the lap must be defective in some way.
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Tue Mar 06, 2018 11:42 pm
Gold Member
Joined: Thu May 12, 2016 2:18 am Posts: 1542
When I had the issue with my BATT Lap it was easy to see the hard spots. They we a slightly lighter color, and became high points in the lap. When the stone went from the hard spot to the normal hardness areas they would gouge. It was a visible difference in the lap.
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Wed Mar 07, 2018 1:51 am
Gemology Online Veteran
Joined: Sat May 22, 2010 2:51 am Posts: 755 Location: South Africa
The BA5T inner band on my Redwing lap soon started shedding particles and developed some unevenness. Sending it back to Gearloose from South Africa was not an economic option so I had it reskimmed locally. It did the same thing again, and so I just use it the way it is, with no ill-effect. Whether this consistutes a defect I don't know. Cast metals often contain segregations and some compositional variation. (The copper outer band has some minor casting porosity, but that doesn't interfere with its performance either.)
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Wed Mar 07, 2018 1:52 am
Moderator: Lapidary Diamonds
Joined: Mon Aug 20, 2012 11:32 pm Posts: 1747 Location: Florida, United States
Lucinator wrote:
tried using the lap like you said. I first wiped the lap clean, then applied PCD 100k diamond stick to the inner part of the lap. Unfortunately I again started to see the same silvery stuff again. Unless im doing something wrong that I'm not aware of then the lap must be defective in some way.
Please post a close-up image of the lap surface. Please keep under 600 px.
Post subject: Re: possible issues with Gearloose Ba5t/zinc+ duel zone lap
Posted: Thu Mar 08, 2018 9:53 am
Moderator: Lapidary Arts and Tools
Joined: Tue Jun 12, 2007 6:41 pm Posts: 5534 Location: Massachusetts, USA
The cast alloys here are deliberately directionally crystallized from the melt, and are "cored" metal. This is why when an edge is smashed in shipping that region is very hard and does not takes a charge well. It is also why people call them "Diamond sponges".
Users browsing this forum: Google [Bot] and 49 guests
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum