rubber rot in the quarter extensions

[tim berry]

ok folks after a brutal winter the snow blower is away. its time to get back on the rear quarter extensions . after long and deliberate thought I think i've solved a very large problem with molding these parts, the internal support structure is going to have to be cut out and discarded because there is no way to get them off the extension without destroying the whole part . the new game plan is to cut the structure out leaving the bolts attached and filling the void inside with foam so that I can control the volume of casting resin used to make the parts ( the stuff is expensive plus i've got 2 gallons about $500 , to get the whole back done). It just needs to be warmer more photos to folow

 

[tim berry]

I've got some more photos last set is just before the clear goes on then molding time

 

[Jack Meoff]

That looks great!

 

[compubert]

Jam up job man!

 

[tim berry]

Clear is on mind you all this work is to make a mold . The things I have learned about these extentions are they suck . I have done these at least 4 times because of them continually cracking. The other thing is they do not like heat the last time I did use heat I was trying to get some of the waves out where the extension sits on the bumber and after sanding I blew it off with air and the whole thing lifted. I though I was seeing things but shure enough all my work had separated from the base material. When I striped the extention I was left with the virgin plastic . Apparently the heat was bringing out either mold release or something else out of the plastic and it formed a barrier and that's what caused the separation . So the way it sits now is the best it's gonna get time to move on .

 

[tim berry]

Here is photos of the material that lifted off

 

[tim berry]

The finish line is in sight !

First layer of silicone on I'm in over my head but it will be interesting for shure ! Here's a couple more photos . I hope to be pouring these by the end of the week

 

[Bruceynz]

3D print the upper door sill mouldings too!

Have a look here about door mouldings

http://www.forfmjbodiesonly.com/cla...rts-We-May-Need/page3&highlight=door+moldings

 

[jasperjacko]

looking forward to seeing the finished product

 

[Jack Meoff]

Same here.

 

[tim berry]

ME TOO ! THANKS FOR THE ENCOURAGEMENT GENTS! second coat of rubber went on this morning, the third will be on tomorrow then I get to do the inside . The dry time is 24hrs so it ain't gonna be this week and you have to build up the material to1/2 to 3/4 of an inch then fiberglass the outside to make a mother mold to support the rubber

 

[tim berry]

Here the exterior mother mold is finished

 

[MiradaMegacab]

:thumbsup:Nice!!!!

 

[Jack Meoff]

The saga continues.
Very nice.

 

[dodger roger]

same here x 2

 

[tim berry]

Almost ready to put the inside mother mold together. Also I took a leap of faith and put some heat on the left extention within 15-20 minutes it was striped of all the paint

 

[MiradaMegacab]

:icon_thumright:Nice progress!!

 

[tim berry]

This taking longer than I planed but hey I hope the quality is there in the end here is some more photos

 

[Jack Meoff]

I'm sure it'll be worth the wait.

 

[Justwondering]

You have done a wonderful job. Excellent photos and very true details of the issues making a mold from thin plastic with inside and outside curves.

My friend and I had a fiberglass company for over 10 years. Making masters (the thing that you could get molds out of, you're calling it the mother mold I think), is a tedious and time consuming process.

Folks never understood why building that initial mold was so expensive. The labor time-sink was horrendous.

If you go down this road again, you might consider using sculpting foam blocks and modeling clay to build the perfect item to get the mold from. Its more low tech but you have so much more control over the shaping. Too low, add more clay. Too high, remove some clay.

The foam blocks were lightweight and used to rough in the structure and then we put clay over the top of that. Smoothing it out as we went. You can also use a heat gun on the clay to remove fingerprints and ridges.

Another technique is to use cardboard and hot glue (good industrial not hobby lobby level). Build out the back of the item with a rough outline of the cardboard glued together as needed. Then put the clay over the top of that. Prepped the grill for a 77-88 ford bronco that way. It worked well, but dang it was time-consuming... 36 grill openings plus the two head lights. Lots of curves.

Best of luck to you and thanks for sharing.