Who owns the Attex Molds

[Tango42]

A few months back I had the great idea to have some skid plates made for attex machines. I created a solid model of one by taking measurements of my body.......



I sent it to a vacuum forming company that we deal with at work. We talked in depth about the part, that is was a skid plate and didnt need to be as pretty as the machine covers they normally do for us. They still came back with a quote of 16k just for the tool (due mainly to its size). I knew it would be expensive, but I didnt think that much. So I basically scrapped my plans for my attex skid plates.....I didnt think there would be many willing to pay $500+ for it.

[femmpaws]

evil, i'm a step ahead of you lol. i started building a large one (not quite wide enough for an attex though) about a year and a half ago...never finished it. plus the attex needs to have a different method. the problem i have is finding something that can vacuum fast enough. i thought about getting a big tank like a large air compressor and hook a vacuum pump up to the tank. then hook the tank up to the vacuum table, and suck it up very quickly! that could be done.

but then i need to figure out how to heat such a large piece of plastic...i went to the junkyard and got LOTS of coils from trashed ovens, but then where will all the power come from? maybe lots of heatguns would be better?!? idk. probably people like matt o would laugh at me for all this, which is perfectly understandable lol. but the first thing is to get a reverse mold made...whether it will be constructed for vacuum forming or glassing...

Well the rule is 10 time min. the vacuum storage area over the the drape area of the part. You also want to be able to pull 25 inches of Hg of vacuum from the start as well. Most people don't understand how much it takes to form a 3/8 inch sheet of plastic.

As for heating you sheets well you need a temp controlled oven, for the heavy sheets you are talking about for the body you would want to use a convection oven as for temp 240 to 280 sticks in my head.

My next question is have any of you priced a large sheet of HDPE in the last month or so?

The nice thing about molding HDPE the mold can be very simple but it has to be very strong to take 2000 lbs a sq. ft. that pulling 20 odd inches of Hg causes. Also the max uses a male mold to form the bodies to just so you know.

Paws

[AndyL]

tango that's pretty cool! and paws 25 hg's sounds familiar to me. the pump that i had was actually for doing ac...it only pulled around 4-5hg's per hour but it could be hooked up to a tank to suck 25 hg's out of it. it has enough strength to do that. as far as heating the coils, i was looking at using the instruments built in the ovens...then again there are many things to consider. while this iea worked for a smaller mold, a different setup would have to be used for something this large and with plastic this thick. if the plastic is over 5mm in thickness, is must be heated on both sides of the plastic. then you need to account for how much it will sag since it's a large heavy sheet of plastic in the center. the biggest setup i believe will be in getting a plug ready to mold plastic on. so, it sounds to me there are three options to continue this process, all three of which will be time consuming but i may go ahead with depending on what comes up:

1. connect with the collector who purchased the molds from richard
2. create a reverse mold out of a durable element such as aluminum or even ceramic would work based on what i've been told.
3. create a reverse mold that one would be able to make fiberglass copies from (not near the expense or time consuming to make since it won't be vacuum formed)

I was planning on creating a male mold. after doing the mods, then turn the body upside down and make the mold from inside...voila! (for fiberglassing any since plastic has shrinkage). There will be much more engineering for the plastic too.

One question though...if fiberglass is much more durable and doesn't weigh much more, why aren't amphib manufacturers using that method today (except for the Hoot)?

Comments/Suggestions?

[femmpaws]

Paws,
Thanks for your input! What do you think the cost and weight comparison would be of an upper/lower tub in fiberglass vs. HDPE? I would just think the fiberglass would have a tendancy to crack if run into a rock while climbing or hitting the ground when jumping. If not, then the answer is simple...the bodies should be made of fiberglass as of now.

Part of the price of making the bodies is getting paid back for the time and stuff that went into making the plug and mold to start with. When you are only talking 10 to 20 bodies the cost is higher then if it was over 100 or 1000.

But my best guess at this time is 1200 to 1600 dollers per body. The cost of resin, gelcoat and fiberglass keep going up. I talked with one of my suppliers and they have had two price jumps in the last 6 months about 3 to 5 % each time.

I'm also playing with ideas about the best way to make the lower hull. The idea I have is make it a male mold so you have hold tight Dim. so your frame will fit like it should and the outside would have glass mat finish so you could repair it and if it was done right you would never know it was done. The top on the other hand I would make a female mold so you can get an showroom finish shine. When I design something I always keep in mind KISS Keep It Simple Stupid,

As for weight I'm not sure but guessing an Attex size body about the 100 to 150 lbs. You don't really know till you build one. I know I could make them 40 lbs or less but they wouldn't last long, knowing you guys!!

Okay with that said I have access to an Attex ST300 it's my understanding it's the first one they made. Who all would BUY a new body if I started making them. Oh and yes when I made the bottom mold I would change it to take the newer 25-27 inch tall tires. BUT keep the top the same after all it is a classic!

As for colors a bright yellow, likely Aztec yellow and forest green and maybe a gray for those that want to paint them.

Paws

[evil8x8]

it would still never be the same as the original brought back to glory thru restoration.

Bridget

I agree 100% but a new "Super Attex" would be pretty cool too!!!

[femmpaws]

One question though...if fiberglass is much more durable and doesn't weigh much more, why aren't amphib manufacturers using that method today (except for the Hoot)?

Comments/Suggestions?

The answer to that question is very simple Grasshopper! CYCLE TIMES.

With a Vacuum-formed hull you have a cycle time of maybe 10 to 30 min. with fiberglass it's 3 to 12 hours depending on the size of the part to days or weeks as in a large boat hull.

Paws

[George]

Okay with that said I have access to an Attex ST300 it's my understanding it's the first one they made. Who all would BUY a new body if I started making them. Oh and yes when I made the bottom mold I would change it to take the newer 25-27 inch tall tires. BUT keep the top the same after all it is a classic!

Paws

Hey Paws,

I believe that the bulk of the remaining Attex frames were built after the ST300 design. The newer frames (1972 and up) have different dimensions and would not fit into an ST300 tub. You might consider using a newer model tub than the ST300.

Just an FYI

[Roger S]

The reason for HDPE instead of fiberglass is durability and flexability. I'd tear up a fiberglass body on every weekend ride.. with what I drive over.

[birddog1148]

As far as heat sources, look at the heat guns used to shrinkwrap boats, basicly a propane powered vortex heat gun, hot and fast. There used to be a conversion for a vw motor air compressor, instead of compressing use it as a vac pump. And there are verry large vac pumps out there, we use old IR T-20 vac pumps at work, and yes we use a tank inline for more efficency. And We also happen to make fiberglass comopsite materials.

Superior Fibers, L.L.C.

HGR Industrial Surplus - We sell everything


What about using a release agent on the mold and using something like a spray-on bed liner?

[amphibious drew]

The reason for HDPE instead of fiberglass is durability and flexability. I'd tear up a fiberglass body on every weekend ride.. with what I drive over.

I agree. Here's another idea. Not sure if it would work, but I see everyone making car stuff out of carbon fiber. Might be a little more than glass, but its light, looks good naked, and stronger than ether option out there so far. Ples you can get pre formed sheets for big parts.