STIHAC

hi guys,

anybody out there can tell me how to mould small parts using microbaloon mix?
how to make the mould etc...
thaks for any info
stihac

MinnFlyer

My Feedback: (4)

Can you be a little more specific? What type of parts are you looking to make?

STIHAC

hi

i'am thinking to make dumy exhaust stacks for my 1/5 scale pica spitfire

stihac

MinnFlyer

My Feedback: (4)

You'd save a lot of time by just making them out of balsa. Just take a piecs od balsa, drill 6 holes (1/4") at a 45* angle and plug them with 1/4" dowels. Then attach it to the side.

STIHAC

hi,

good idea. maybe i'll try that.

stihac

Roby

I did cast scale exhaust stacks for my Dynaflite Spitfire
with Z-poxy finishing resin and Micro balloons, worked fine
and looked very scale.

This is what I did :

made a plug from balsa of exactly what I wanted

coated plug with finishing resin,wet sand until smooth

mounted plug to a piece of lite ply

apply mold release

used "mold maker" (follow directions)

cast away with Z-Poxy finishing resin and balloons

the mold can be used over and over


Regards
Roby

STIHAC

hi roby,

thank you for reply.
great info.

petr

foxx

My Feedback: (2)

Roby where did you get the mold maker and mold release thanks

Roby

The latex "mold maker" was purchased at my LHS.
I'll dig it out and get the manufacturers name for you.
I don't remember where I got the release, (DOW Corning)
but I'm sure that anyone selling glass cloth in the magazines
can help you

Hey Stihac I found a spare mold that I had made
a while ago for my Spitfire Mark V. It is a backup
mold in case my favorite got trashed. It's a little
on the light side but I've made several good parts
off of it with no problem. Your welcome to it.


Regards
Roby

STIHAC

hi roby,

that sounds great. if you can spare it . please email me how can we do it.

stihac
[email protected]

foxx

My Feedback: (2)

I was going to order some mold release from CST, but they told me $25 extra for shipping hazardous material. what !. I am thinking to try spray type silicon lubricant from auto parts store, it might work

Flyboy Dave

My Feedback: (21)

Silicon will release the mold just fine....but you'll
never be able to paint the part.....

Use regular 'ol car wax, then use "Body-Prep" to
remove the wax....then prime, and paint.

foxx

My Feedback: (2)

Thanks Dave for the info. I will try car wax method. Amazing learning never stop.

Flyboy Dave

My Feedback: (21)

Wax the heck out of it....3 coats, buffed between coats.
When you trim the part (cutting off the excess material)
leave one little edge about 1/2 inch long....sticking up about
1/8 inch. Use this "lip" to get in and remove the part from
the mold. Pop the part out of the mold when it is about 85%
cured...(still semi-flexable) with a stiff rubber spatula....
(won't scratch the part)....


Dave.

Merlin65

Hi all.
The exhaust stubs shown in the pic are for a Mk VIII Spitfire. They are made with modelling clay for the mold master which is used to make latex molds. No release agent or polishing required.

The procedure is as follows:-
1. Carve the clay to the final shape.
2. Cut the master in halves.
3. Stick each half to a flat surface and apply 2-3 coats of latex.
4. Peel the latex molds from the masters.
5. Apply z-poxy to the mold halves. (Gel coat?)
6. When dry, apply more z-poxy and one layer of 7oz glass strips. Allow to dry.
7. Apply a second layer of glass, preferably running 90 deg to the first layer and when dry, peel the latex from the glass parts.
8. Zap the halves together and reinforce the joints with z-poxy and glass strips.

The latex is virtually indestructable and is water soluable for easy cleanup. Both clay and latex are available from any craft supplies store.
--
Merlin

Roby

Merlin

VERY nice !

Roby

Merlin65

Thanks Roby.
This was my first attempt at this method and I made a few mistakes, including sucking one of them up while still wet with a shop vac. Hence the dark appearance of the top half of stub no 2.
I think they will look better when painted.

I should also add that I drew up plan, side and end elevation templates which were stuck to the clay to aid carving.
--
Merlin