Forums
New posts
Search forums
What's new
New posts
Latest activity
Articles
Members
Current visitors
Log in
Register
What's new
Search
Search
Search titles only
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Lab talk, the good, the bad, and the ugly
Porcelain
cracking porcelain on long span bridge
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="ztech" data-source="post: 199475" data-attributes="member: 3022"><p>A common problem to address in a case of this size is the heating and cooling of the alloy and the porcelain maturation as mentioned above. On a case of this size I routinely increase the high temp by 5-10 C and increase the high temp hold by up to +75% on the first bake to overcome the mass of material that is heated. Under matured porcelain close to the alloy interface will wreak havoc on subsequent layers that will easily mature over them. I would also add a slow cooling time of 6-10 min. As for the design, I almost never expose metal unless needed due to lack of space. I also agree with Bob, the span of this bridge exceeds what I would feel comfortable making. It would go out with a lot of disclaimers.</p></blockquote><p></p>
[QUOTE="ztech, post: 199475, member: 3022"] A common problem to address in a case of this size is the heating and cooling of the alloy and the porcelain maturation as mentioned above. On a case of this size I routinely increase the high temp by 5-10 C and increase the high temp hold by up to +75% on the first bake to overcome the mass of material that is heated. Under matured porcelain close to the alloy interface will wreak havoc on subsequent layers that will easily mature over them. I would also add a slow cooling time of 6-10 min. As for the design, I almost never expose metal unless needed due to lack of space. I also agree with Bob, the span of this bridge exceeds what I would feel comfortable making. It would go out with a lot of disclaimers. [/QUOTE]
Insert quotes…
Verification
Who do we work for?
Post reply
Forums
Lab talk, the good, the bad, and the ugly
Porcelain
cracking porcelain on long span bridge
Top
Bottom