Great Video: Casting a Part With Polyurethane | Part 2

BJBEnterprises
BJBEnterprises
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Published 2014-04-23
Welcome to Part 2 of BJB's Mold and Part Making Video Series! Using simple methods developed over decades in Casting, Rapid Prototyping, Movies, DIY & much more... learn how to cast high quality Polyurethane parts in the silicone mold made in Part 1 of this series. BJB is the industry's preferred resource for "Taking the Mystery Out of Materials".

Part 1 Video here:    • Great Video: How to make 2-Part Silic...  

Company Website - www.bjbenterprises.com/
Phone - 714-734-8450 (USA)



For 40 years, BJB Enterprises, Inc., an ISO 9001:2008 Company, has been in the business of formulating and supplying quality liquid resin systems to a vast array of industries and with a myriad of applications in mind!

BJB offers a complete line-up of Castable Polyurethanes, Epoxy Systems, Silicone Casting Rubbers, Polyurethane Foam Systems, Aliphatic Water Clear Urethanes, Sprayable Polyurethanes, Pigments and Release.

www.bjbenterprises.com/

0:00 Introduction
1:56 Exothermic Reacts/heats faster with increased mass.
2:12 Temperature Affects Work-Time
2:45 High Viscosity = Thick
2:50 Viscosity Centipoise (CPS)
5:22 "Paintable" Mold Release
5:25 E302 Rocket Release
5:49 Silicone Oils can transfer to the part.
6:00 Mold Release can Limpart a texture.
6:16 E236 Urethane Release
6:23 Don't flood the surface!
6:31 Don't spray release in casting area!
6:41 Allow a few minutes before closing mold.
6:59 The mold is clamped between two boards to close seam line.
7:51 Vent Risers & Fill Funnel create reservoirs to account for material shrinkage.
8:31 Rolled Funnel
8:45 Smaller Cross Section • Increased Head Pressure
8:54 Paper can cause moisture contamination!
9:24 Dispense Equipment
10:12 9-Min Work Time 1000 CPS
11:07 2% X 100g = 2g 6821 Cherry Red Pigment
11:15 Don't mix 3 components together at once!
12:04 Double Mixing
14:04 Heat promotes quicker demold
14:29 Pressure does not force air out of the mold.
14:43 40-80 psi common pressures
All Comments (21)
  • @lundertied9966
    One of the best videos on the topic I've seen so far, informative and concise. Thank you!
  • @msantana4422
    Thank you. I watched some non-professional videos before and the difference and quality you achieve here is enormous. You speak at a good pace so we have time to actually listen w/o need of going back so often. I also appreciated the science on it, because to achieve quality one has to consider the properties of different materials.
  • @KKALFAKIS
    exellent video. Excellent technical coverage, excellent comentator, clear speach, easy to understand. Bravo !!
  • @Colorcrayons
    "A hatchet? A gun? Nah, I'll just use the screwdriver..." XD Thanks for the informative videos. They put the Smooth-On product videos to shame. Such professionalism makes me inclined to choose your company as my source for RTV and Polyurethane materials.
  • @paulrmoss
    great video, very clear and well done
  • @samson8146
    Sure I learned many things about casting and molds.
  • @AndreBynoe1
    Fantastic information, both part 1 and 2 videos.
  • @BombedNevada
    Very instructional video. Now i just need to build my cast and figure out what material is best for a snow sled.
  • @TrumpsBookie
    Great Vid!  I just started at a urethane supply company and need to understand the process.  Very informative. Well done
  • @NoahSpurrier
    This is one of the better intro videos for casting I have seen. The only step that I think was missing is using a vacuum chamber after the mold has been filled with material. This can help dislodge any small bubbles that tend to form around troublespots. Vent tubes are not always sufficient. Under vacuum material will flow backward through the fill and vent tubes. It shouldn't make too much of a mess if your tubes are long enough and assuming you had not trapped any huge bubbles. I make the material to flow back and forth a few times by cracking the vent petcock while the pump is running. Follow this with curing under pressure and you should have no bubbles or voids. Note that if your mold itself has any bubbles or voids then curing under pressure will distort the mold. You don't want any bubbles, not even the tiny, almost invisible ones. The mold will shrivel while under pressure.
  • @2010reaper
    I am a little upset that the Luger was not used as improvised scissors..
  • @robbowman8770
    Thanks for the excellent videos. Really good to see so much attention to detail and passion for quality. Makes me confident that you care about your products, too. I have an idea to do some prototyping of ultra high precision electronics, where I would make a Silicone mold to accurately 'pot' small irregularly shaped circuit boards. Time for some more research on your website ...