ATTENTION: As of March 2017 the Resin Addict Forums are being wound down.
New members are no longer being accepted. Read more about it here.

Resin question

Questions and discussion of tools, materials and techniques.

Moderator: Wardens

Resin question

Postby blacksmithn » Thu Jul 30, 2015 8:19 pm

I am currently looking at a couple of resins available from eBay vendors. The first is from a company called Specialty Resin and they have a "slow cure" polyurethane resin with a 6 minute pot life, 1 US gallon for roughly $72, including shipping. The second is from a company called Magikast, and they have a 2 gallon polyurethane resin with a 5 minute pot life for $91 with free shipping.

I have used a Specialty Resin p/u resin with a pot life of 2 minutes which, although I like the end product, is just way too fast for me. I have also used Magikast silicone for molds and have no complaints there. So, I guess my question is what qualities besides price do I look for in making my decision? Is anyone else familiar with these particular companies or products?
blacksmithn
Casual
 
Posts: 20
Joined: Mon Jul 20, 2015 8:11 pm

Re: Resin question

Postby RageofAchilles » Fri Jul 31, 2015 6:10 am

I know there is a temptation , especially early on to go with bulk purchases of cheap resin. the problem is if you find you don't like it your stuck with a whole lot of it. Also if your not making hundreds of casts in quick order, a bulk resin will lose it's shelf life while it sits around.

What I have found with cheap resins is that they tend to be brittle, something like your flat car would tend to shatter if dropped on a hard floor for example, whereas you could pay more and get a resin which is more akin to an ABS plastic. Buy sample sizes until you find something that really fits the job.
User avatar
RageofAchilles
Habit
 
Posts: 249
Joined: Fri May 09, 2014 4:14 am
Location: West Sussex

Re: Resin question

Postby mangozac » Fri Jul 31, 2015 7:46 am

I too recommend getting your hands on a small sample quantity first to see if you like it. Brittleness/hardness is one of the factors to take into account: you don't want the resin to cure too hard as a little flexibility prevents parts from breaking easily. Note that you don't want it too soft either as cleaning up parts becomes a headache. Shore D 65-70 is the target hardness range IMO.

Note also that some resins behave differently than specified in their datasheet based on the part thickness. There is a resin available here in Oz called 4PU and while it's beautiful to work with on larger parts, fine parts like I cast don't generate enough heat to cure properly and remain very soft. The only way to find that out is by testing.
Oh yeah I can make that....
User avatar
mangozac
Resin Addict Collaborator
 
Posts: 4271
Joined: Fri Oct 16, 2009 3:40 pm
Location: QLD, Australia

Re: Resin question

Postby blacksmithn » Fri Jul 31, 2015 9:54 pm

Well, I WAS looking forward to having a large supply on hand, but you guys make good points. As far as hardness ratings go, the 2 minute Specialty Resin stuff I have on hand has a rating of 75. The slow cure from Specialty Resin has a hardness of 70. Is 5 points on the scale going to make much difference?
blacksmithn
Casual
 
Posts: 20
Joined: Mon Jul 20, 2015 8:11 pm

Re: Resin question

Postby mangozac » Mon Aug 03, 2015 8:25 am

I would argue that 70 is even better ;)

By all means, buy up big once you've qualified the new resin product (so long a you think you can use it all within six months)!
Oh yeah I can make that....
User avatar
mangozac
Resin Addict Collaborator
 
Posts: 4271
Joined: Fri Oct 16, 2009 3:40 pm
Location: QLD, Australia


Return to Dr Polymer

Who is online

Users browsing this forum: No registered users and 20 guests

cron