PR ..Questions

[Darley]

few days ago I did some casting again, beside the rattle snake Baron every thing when wrong[xx(].
I set myself for 2 Baron and 2 Cigar pens, I did 1 Baron with snake skin the rest with Barramundi fish skin, fish skin whent black same as a coldron bottom, ( don't know yet if I have to salvage the tubes or buy new tubes set ), anyway I did have a talk with one of the Y! penturner about casting and in particular for bubbles, this person saying that I should put in pressure container at 50 PSI because is the way comercial people do, do some one here do/ try this type of method?.
When I did my casting I put 6 drops of MEKP per oz do you think is to much? the same person sugest that MEKP may react to CA ( I glued the fish skin with CA ) in another matter MEKP may react as well with the dye use for the fish skin ( hide ) .

I see a lot of good casting in this site, do some one could explain what I'm doing wrong? do I have to put less MEKP? do I have to put my casting under pressure? .

Any help, ideas or comments are welcome

 

[alamocdc]

Serge, I used CA to glue my material to my tubes for casting and didn't have a problem. However, I only used 7 drops of MEKP for the total mold so 6 drops per ounce may have heated it up a bit and could be your problem. I accidently used that much a few weeks ago in another casting and it cooked very quickly. It was cured enough to turn in about 8 hours and popped free of the mold in 4 or 5. It took me a bit to figure out what I did wrong. The PR is still usable (in my case), but it is pretty brittle and you have to be more careful when turning it. Salvaging the tubes shouldn't be a problem.

 

[Darley]

Billy thanks for the comment, could you tell me what is the capacity of your mould? 3oz, 4oz? I think too,I should use less MEKP, but do you think the dye use for colouring hide could react to the MEKP? what about the bubbles how to prevent them?

 

[rtjw]

Serge I have gotten down to 4 drops per ounce on my castings. I have a 3 inch by 6 inch by 1 inch mold that holds nine ounces.

It does sound like you cooked your molds. It all depends on your weather.

 

[Darley]

Johnny when I did the casting it was pouring buckets ( I mean raining heavily )do you think humidity in the air affect casting? will reduce the MEKP on my next PR

Edit: my mould are 3" square by 1" high, I cast only 4 tubes in each

 

[alamocdc]

Serge, I use both 4 and 9 oz molds, but for casting like this I use primarily 4 oz. I used to try to do the drops per oz thing but I didn't like the varying results I got with it. The instructions on the last bottle I bought said only to use 7 to 10 drops for every 3/4 inches of casting and nothing about ounces at all. I tried it and have been quite happy with the result. One took several days to cook off because of the material I had in it, but it finally did and I got a good casting.

 

[Darley]

Billy look like you use 3 drops per oz, will have to try again with less of MEKP, Thanks

 

[Fangar]

Serge,

What are you plugging your tubes with? If the base wax, and you use to much hardener, you will get tons of heat (I have melted trays before). This will cause the base wax to melt, and thus allow the air in the tubes to escape resulting in bubbles. Try around 3-4 drops per ounce, or less and let em sit. They will eventually even set without the hardener over time.

Fangar

 

[Darley]

Originally posted by Fangar
<br />Serge,

What are you plugging your tubes with? If the base wax, and you use to much hardener, you will get tons of heat (I have melted trays before). This will cause the base wax to melt, and thus allow the air in the tubes to escape resulting in bubbles. Try around 3-4 drops per ounce, or less and let em sit. They will eventually even set without the hardener over time.

Fangar

Don't laught James but I use potatoes[], like Anthony told me I got french fry [][]