PR blanks soft/gummy in middle--- how to fix them?

Signed-In Members Don't See This Ad
redfishsc

redfishsc

Member
Joined
Feb 11, 2006
Messages
2,545
Location
North Charleston , SC
I have some blanks that are cast with some sentimental-value bamboo from someone's back yard. I need to get these particular blanks to harden if possible.

They were cast several days ago. The resin is about 8mos. old (opened).
I catalyzed it with about 10 drops per oz b/c I ran into this problem on some other blanks a couple weeks ago and I assumed that the older resin needed some more catalyst to kick over.


They are 3/4" cast in PVC.


Would giving them 10-15 minutes in the oven at about 160F harden them?

Any advice is greatly appreciated!!

Matt
 
Signed-In Members Don't See This Ad
Cool. I pray that this works! I have them roasting in the oven right now--- my oven is hovering from 150 to 180 (using a digital thermometer) and they've been in there for 30-45 mins. I'm going to give them a bit longer just in case.


Do I need to suspect the PR or the catalyst as being too old to be useful? (no offense, Ed4copies:rolleyes:)
 
Well, I baked them until their timer popped out ;) and the ends where I had trimmed them with the end-mill seemed to be nice and solid. Hopefully this worked! Now the apartment smells like bondo.
 
i have a dedicated toaster oven down in the shop just for castings that remain sticky when they shouldn't.
works everytime. 150 for 15 mintes and i usually do three cycles....just to make sure the heat gets to the middle
 
hewunch said:
I bet the neighbors are really happy with you right now. So who's bamboo is it? Keith's?
Click to expand...


Keith....who? Dr. someone?

They actually are bamboo from one of the library employee's homes who lives very near campus. You might know her (don't wanna use her name online) but she's been an employee for eons and is a very sweet lady.
 
hughbie said:
i have a dedicated toaster oven down in the shop just for castings that remain sticky when they shouldn't.
works everytime. 150 for 15 mintes and i usually do three cycles....just to make sure the heat gets to the middle
Click to expand...


That's basically what I did, but I just left them in for the full duration. Seems to me like they would harden more into the middle if they were not done in cycles, since the outer parts would cool off (thus cooling the middles) in between cycles.

Either way, what you are doing works, we'll hope what I did works. The blanks were baked with the tubes epoxied in--- I didn't notice they were soft until I trimmed the ends up (which explains why they drilled so easily). The epoxy seems to have taken the heat very well. So far:redface:
 
Considering I had a jug of it to cure in the heat with NO catalyst, I'd say adding a little heat would be a good bet.
 
skye, from what I've read on other threads you need some temperature control my friend! a little insulation, a window air conditioner, something man! You make such nice pens its a shame that all the planets have to align under a full moon for you to be able to turn!:frown:
 
actually, what i had meant.......either before the timer goes off or immed after, i set it to another cycle....not letting it cool....so i actually give it about 45 minutes at 150......anywho....it works......and at 150.....it doesn't 'melt' either.......DAMHIKT
 
I have to say that you probably shoudn't be cooking this in a oven, in your place of residence. Fumes aren't safe.

Did you use your stove or a non-food bearing toaster oven? I bought a toaster oven at a retail store for 19$. It works amazingly well for this task.

I have seen on other site where people have made a heating box out of plywood and covered with unsulation on the inside and then they have a 40 W incandescent bulb inside of the box to keep it warm. That kind of idea would work on a grand scale. It could actually be made large enough to support a pressure pot.

What do you guys think of that? Any flammability issues?

Grub32
 
In order to control fumes, I built a "finishing" box out of plywood with a plexiglass front. I hooked up a bathroom ventilation fan blowing into the box (with a filter on it so I'm not blowing sawdust onto my finish pieces), and a dryer vent coming out of it going outside. I built it large enough to accomodate my p/v pot or a toaster oven. All of my harmful fumes then go outside and not in my nose. I use this for casting esp, but also for poly and lacquer and other things that take a while to cure to have them in a dust free environment.
 
Wow would you mind showing a picture of that? I would love to use that for my p pot when I get it this next rebate check. I do all my work in the basement so fumes can be a problem.
 
redfishsc said:
Keith....who? Dr. someone?

They actually are bamboo from one of the library employee's homes who lives very near campus. You might know her (don't wanna use her name online) but she's been an employee for eons and is a very sweet lady.
Click to expand...

Oh, I have a good idea who you are talking about. And having just browsed the school website, I see my former Prof of Missions is no longer @ the school.
 
I got those pens done, here they are! I posted them over on SOYP but I wanted folks who replied here to see how they turned out. I was pleasantly surprised!


bamboo_black2.jpg


bamboo_black1.jpg


bamboo_blue.jpg


bamboo_red.jpg





Hewunch--- Yes, Keith is no longer here but he is a beloved legend around here--- they named an auditorium after him when they built the new Missions building. The auditorium is, by far, the most comfy classroom I've been in---- theater-style seats.... snooooooooze.....
 
Last edited:
rjwolfe3 said:
Wow would you mind showing a picture of that? I would love to use that for my p pot when I get it this next rebate check. I do all my work in the basement so fumes can be a problem.
Click to expand...
I'll try to get a pic up soon....I'm doing a little "renovating" of the box at the moment, but I'll try to get pics up as soon as I can.:rolleyes:
 
grub....i bought a cheap toaster oven JUST for t his.....that way i don't have the smell and fumes roaming around in the kitchen and living areas.....

those pens turned out great......good job
 
You must log in or register to reply here.
Back
Top Bottom