Earl Jr. 3: Klein's Bottle of Infinity
Runtime: 62 minutes
We are pleased to present contemporary American glass artist Darron Hensley, also known as Earl Jr., in this in-depth E-demo focused on advanced borosilicate lampworking and complex hollow forms.
This E-demo is designed for intermediate to advanced lampworkers interested in scientific glass techniques, sculptural problem-solving, and the precision required to execute technically demanding forms at the torch.
In this demonstration, Earl Jr. guides viewers through the construction of a borosilicate Klein bottle—a form that merges conceptual geometry with rigorous technical execution. The project functions as a focused study in airflow management, heat control, tack welding, and sequencing operations to successfully resolve complex internal and external connections.
Throughout the demo, Earl Jr. emphasizes planning and order of operations, showing how strategic decision-making can prevent unnecessary reworking when dealing with acute angles and fragile fusion points. Viewers will learn how to distinguish between temporary tack welds and permanent fused connections, and how to manage these transitions safely while maintaining structural integrity.
The demonstration also explores advanced heat management, including the use of annealing and plastic heat states to maintain a stable working base and avoid stress or devitrification. Gravity is used as an active shaping tool, supported by constant multi-angle observation to refine form and alignment as the piece evolves.
Beyond the Klein bottle itself, this demo develops patience, precision, and a deeper understanding of how borosilicate glass responds to heat, airflow, and gravity—skills that translate directly into both sculptural and functional glasswork.
Techniques shown are intermediate and require patience — expect challenges, repairs, and learning moments as part of the process.After purchase, access may take up to 24 hours to activate. Learning options and access details are outlined in the Learning Tiers section.
Skill level: Intermediate – Advanced
Process: Lampworking / Scientific Glass (Borosilicate)
Demo runtime: 62 minutes
Requirements: Your own torch
Our Learning Tier System - Graduated Support
Learning Tiers
Choose the level of access and support that best suits how you like to learn.
All tiers include access to the full E-demo; the difference lies in the duration of access and the level of support provided.Tier A — Watch Only
A self-led option for focused viewing and inspiration.
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Watch-only access to the full demo for 6 months
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Learn at your own pace with pause and replay functionality
Best suited to students who want to explore the technique independently, without additional materials or mentoring.
Tier B — Supported Learning
For learners who value reference material alongside the video.
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Everything included in Tier A
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Complimentary downloadable course materials
(reference images, notes, diagrams, and/or process guides) -
Watch-only access for 6 months
Ideal for students who want structure and resources to support practice at the torch.
Tier C — Mentored & Certified
A guided learning experience with personal support and lasting recognition.
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Everything included in Tier B
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Extended access for life to the demo
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30-minute one-to-one online consultation with Zurich Glass School
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Official printed Certificate of Completion, posted to you from Switzerland
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Priority support during your learning period
Designed for students seeking guidance, confidence, and formal recognition of their learning.
Access is activated after purchase and may take up to 24 hours.
Consultations included in Tier C must be booked within six months of purchase.-