Packard Forum Index » V-8 (1955-56)

Out of silicone rubber and it's a challenge because of the thin sections and undercuts. Have some different casting material coming next week with longer pot life for another go. The stuff I'm using now only has 3 minutes before getting hard--too short to work the air out.

what about using a JBWELD type material????? Altho JB weld is rather expensive maybe a bulk container order mite be a lot cheaper?????

JB weld is too thick. The stuff has to be almost like water to flow into the tiny spaces. The grill bars & sides only about 1/16 thick. That's the problem I'm having. The originals were injection molded and that filled the nooks & crannies but these have to flow and let the air escape at the same time.

maybe place the charged mould into an air tite box. Draw a vacuum on the box for maybe 5 minutes. The only problem with that is that u need a way to continue pouring a small amount into the mould to make up for the air loss.

I put a cottage cheese container of plastic in an old pressure cooker. I have a hose fitting screwed into the lid of the PC. I attach a hose from the lid to a device made by Fisher Scientific that has a threaded end for a garden hose. When a stream of water is forced through the device it causes a vacuum in the PC and pulls excess air from the plastic.

The extra plastic needed when pouring could be accomplished by having an extra-high gate which would hold a little more material than required.

All good ideas and I've tried variations. I think the problem is the pot life of stuff I'm using--3 minutes from mix to too thick to pour--just doesn't allow it go get to the thinner areas in this complicated a piece. Have tried doing in sections and that worked but too easy to misalign mold. Stuff coming next week has a 20 minute life. Will probably try spincasting as well with it--drawback is it has to sit in mold for several hrs. Will keep trying and let you know how it turns out.

I attach a hose from the lid to a device made by Fisher Scientific that has a threaded end for a garden hose. When a stream of water is forced through the device it causes a vacuum

Randy, every chemistry lab has that device and on close examination it should look very familiar to you, it's really just a venturi like the ones in your carburetor, except it uses the passage of water thru the venturi rather than air.

Chek the expansion rate on the mixture. Don't want it to break the mold.

HH56. Does your car have factory air or are u adding it yourself?????

I've read and studied the AC Install pdf. But refresh my memmory. Does the Evaporator plenum replace the defroster plenum or just bolts onto it creating a kind of double plenum.????


Would it be feasible to cut a round hole in the Evap plenum and mount a squirl cage fan to it????? That would freee up the left freshair duct for the PowerBrake conversion. Not sure why Packard didn't do it that way but my knowledge of the factory AC is limited to the AC Install PDF on this forum.

PV8: Car has fact air that I installed from a Parts car. The entire black box unit shown in pict above in post 47 totally replaces everything under the dash. There is no place for a blower inside with this arrangement as it pretty much fills the front under dash--even the glove box has to be shortened by about 2 inches

The heater is in eng compt & still blows in at the same spot but is directed into the AC box where it comes out the vent on the bottom or can come out the AC ducts. The original Right air vent is blocked off and the box over it--so all fresh air now comes from Left. The defroster feed is a single opening now with the two original small ones blocked off and a big one cut just over the diverter flap into the air channel.

The AC blows in on the top left of evaporator and goes down then out the front on the little angled piece to the ducts. The left air vent knob now has full range & reads OFF, AIR and COLD but for the most part works just as the heater side did with OFF being no outside air so total recycle for the AC because it draws from L inside vent, AIR blowing straight thru and COLD supplying outside air only to AC Blower.