Molding New F-86 Drop Tanks
 

After a couple of years of abuse and repairs, I decided to make new drop tanks for my F-86. With the guidance of Jeff Minotti, I started the process. First was to take one of the better of the two drop tanks and make a finished in primer tank. I then made the parting board and filled the small gap with clay to make the corner. This will be the top edge and center line of the half's when the mold is done. I laid up the glass today. it took a good 7 hours. I used the West System epoxy with the medium cure hardener.

Here a a few pics. I will post more as the process continues. This is only Half the mold.

RE: Molding New F-86 Drop Tanks
 

What's the Dimentions of your tank? Looks like you got it going on.

RE: Molding New F-86 Drop Tanks
 

Tanks are 22 inches long and about 3 inch in diameter at the widest point

Joe

RE: Molding New F-86 Drop Tanks
 

Joe. That's a good size to work with. PM sent.

Roy.

RE: Molding New F-86 Drop Tanks
 

I took the parting board off today. It came off a lot easier then I expected. I will get the other half done this weekend.

Joe

RE: Molding New F-86 Drop Tanks
 

Nice job there joe.

RE: Molding New F-86 Drop Tanks
 

Joe what did you use for mold release? (looks very clean)

RE: Molding New F-86 Drop Tanks
 

I have to do eaxactly the same job & have had no experience with mould making.

I'll be watching with interest, thanks for posting. - John.

RE: Molding New F-86 Drop Tanks
 

Ok I managed to get the other half of the mold set up today. I took step by step pics and I will try to explain what I did.

The first pic and second is of the West system that my friend Jeff set me up with to use. The wax and Partal where his.

RE: Molding New F-86 Drop Tanks
 

First step I put 3 coats of wax on the plug. I waited about 15 minutes between coats then buffed each one.
Second is the Partal Mold release liquid. It is recommended to spray on a thin layer or you can use a small foam brush. One coat is sufficient but don't get it too heavy as it will run.

RE: Molding New F-86 Drop Tanks
 

Next a fillet layer where the plug and the parting surface meet. This is made to the consistency of peanut butter.

RE: Molding New F-86 Drop Tanks
 

After the fillet layer tacks up, with the 206 hardener about 45 minutes to an hour, A gel coat is made to the consistency of ketchup. This goes over the entire plug and parting board.

Make sure there is are no see through places where you can see the plug or the parting board/surface.


After the gel coat tacks up, again 45 minutes to an hour with the 206 hardener, you are ready for the fiber glass. I used 2 layers of 6 oz. cloth. mix a wet coat of epoxy set the glass in place and wet the entire area out. Do the same withe the second layer of glass.

after this layer tacks up the filler materiel is applied then 2 more layers of glass cloth.

This pretty much completes the mold now it sets for 24 hours before it is separated.

Joe Lewis
Kingtech
K-80 and K-140
Owner

RE: Molding New F-86 Drop Tanks
 

This morning I pulled the molds apart.

I am using Klecos for the alignment pins and to pull the molds together. The holes are drilled before the molds are separated. They came apart pretty easy.

There are a couple of small spots where the primer from the paint stuck to the mold. No big deal here, I wll just wet sand it with some 600 grit.
After this is all done the molds need to be washed then 3 coats of wax and 1 coat of the Partal film.
I might try to set a tank up today.

RE: Molding New F-86 Drop Tanks
 

To see my approach to tip tanks and pods go to:
http://www.sidgates.us/HOBBIES/F-94C/F94C%20PROJECT.htm

Then click on "Tips Tanks and Rocket Pods"

RE: Molding New F-86 Drop Tanks
 

Sid

Very nice work. Unfortunately my tanks are not round enough to put in a lathe. I did manage to get the first tank half's made up. I plan to let it set up completely then I have to glue in a ply plate for the attachment screws. I have some carbon fiber materiel that is some what stiff before epoxy. I will glue this in after to make a lip then assemble the half's

Joe Lewis
Kingtech
K-80 and K-140
Owner

RE: Molding New F-86 Drop Tanks
 

Very nice work there Joe!!

RE: Molding New F-86 Drop Tanks
 

By "filler material" I guess you are talking about the white strips that appear to be added to thicken the wall of the molds halves?
What material did you use for this?

RE: Molding New F-86 Drop Tanks
 

Joe takes extra pics for this step. I have had trouble joining parts with no hole in them. Great looking work BTW.

I have found for a clean seam I need those molded bumps in the parting planes, plain screw holes did not line both mold halves well enough, anxious to see how the clecos work.

RE: Molding New F-86 Drop Tanks
 

It appears to be Soric XF2 (also renamed Aeromat)

RE: Molding New F-86 Drop Tanks
 

The material is called Coremat and is used to stiffen up the molds so you can use less layers of glass cloth. It can be bought at http://www.cstsales.com/products.html

RE: Molding New F-86 Drop Tanks
 

Jeff
Thanks for the info. I was not sure what the name of the material was. I will get some more pics of the half's after I remove them from the molds.

Joe

RE: Molding New F-86 Drop Tanks
 

Great job! You dont have to wet sand out the primer from the mold. A little acetone will dissolve it. I have been there. :) Again, great job on your mold!

RE: Molding New F-86 Drop Tanks
 

After a few heck-tick days I sat down tonight and removed the tank half's from the molds. I have to say I am pleased with how they turned out. I used the gel coat, a layer of 1 oz. cloth and 2 layers of 6 oz cloth. I also added some carbon fiber strips where the ply plate will be glued in. I will try to get the half's joined by the weekend. I am not sure what I am going to do yet but I have a couple of ideas.

Joe Lewis
Kingtech
K-80 and k-140
Owner

RE: Molding New F-86 Drop Tanks
 

They look real good Joe. See it was worth the time it took to make the molds. How did they release from the molds?

RE: Molding New F-86 Drop Tanks
 

I had to do some pulling on them. I ran an X-acto blade around the edge to just get them loos from the mold.