Proving the old saying 'Ask and ye shall receive', Zoran saw the thread about my SV/MV project and the carbon tank I'd made. He also saw my reply to a question about how much it would cost for me to make a tank - to which I replied something like "I don't want to turn the hobby into a job and I prefer to make things like this for friends...'
Zoran's next post started out with "Well, my friend..."
Long story short, I've decided to build a carbon/kevlar tank for Zoran and his race SV. I thought you all might enjoy watching the start to finish process. I'll be posting as I move through the project and hopefully this will dispell some of the the black art and mystery around composites.
For those of you who've not seen the tank I made for my SV, (pic attached) I think you'll be surprised at what a hobbiest can achieve in the privacy of his or her garage. Perhaps after watching this project come together, some of you will be motivated to give it a try! I'm half tempted to host a 'come to Petaluma and learn how to make composites - maybe an exhaust hanger or something simple...anyone interested? I'd charge for cost of materials only...it'd be a hoot. Give me a holler if you want to know more.
So anyway, let's get going. I've not even started but let's look at the process I'm going to use. There are any number of ways to do this, which is half the fun - there are almost no rules...but here's what I like to do:
1. I'm going to start with a stock SV tank, fill in the gas cap area and modify the area around the seam that joins the top and underside stampings to make a more 'composite production-friendly' shape - more on this later in the project.
2. Once I have a shape I like, I'll make what's called a 'splash mold' (a non-production quality mold) of the top and the underside.
3. I'll use the splash molds to make fiberglass-only parts that will be bonded together to make what's essentially a fiberlass replica of the stock tank.
4. Zoran, an experienced crasher of SVs, has proven that the sides of the stock SV tank stick out too far and are very susceptible to damage - see attached pics of the fabulous donor tank he's provided me as the starting point... So, I'm going to modify the fiberglass replica and narrow it as a pre-emtive design modification to combat the literal impact that might occur when one combines gravity and asphalt.
Note: Carbon fiber won't dent, it'll crack and break and splinter and grind away to dust if you impact it (with enough force) or drag it across a rough surface. It's not impact resistant. That's what the Kevlar is for.
4. Once these mods are all done (lots of bondo, popsicle sticks, and hot glue!) I'll have a model of the final shape I want. This is called the 'plug'. And now it's time to sand, sand, sand to get the finish as close to perfect as possible.
5. Once the plug is finished, I use it to make the production molds. It will likely be a three piece mold: a two-part top is needed if there are any combined surface angles that would cause what's called 'mold lock'. Think of making a mold using a lightbulb - you couldn't get it out of the mold unless the mold could be split. So the top will utilize a 'splitter plate'. I'll need to make one in order to make the splash mold so you'll see one of those soon enough...
6. Finally, once I have the production mold, I can layup the parts and make the tank. Or should I say tanks!
7. I may decide to make these available to others, we'll see. Depends on demand, how labor intensive they turn out to be, etc.
Zoran will likely not be greeted by a large, lightweight Christmas gift but I'll work on it as time permits.
So, stay tuned and feel free to contact me with questions, comments, etc.
Chris Baker
chris.b.baker@kp.org
Zoran's next post started out with "Well, my friend..."
Long story short, I've decided to build a carbon/kevlar tank for Zoran and his race SV. I thought you all might enjoy watching the start to finish process. I'll be posting as I move through the project and hopefully this will dispell some of the the black art and mystery around composites.
For those of you who've not seen the tank I made for my SV, (pic attached) I think you'll be surprised at what a hobbiest can achieve in the privacy of his or her garage. Perhaps after watching this project come together, some of you will be motivated to give it a try! I'm half tempted to host a 'come to Petaluma and learn how to make composites - maybe an exhaust hanger or something simple...anyone interested? I'd charge for cost of materials only...it'd be a hoot. Give me a holler if you want to know more.
So anyway, let's get going. I've not even started but let's look at the process I'm going to use. There are any number of ways to do this, which is half the fun - there are almost no rules...but here's what I like to do:
1. I'm going to start with a stock SV tank, fill in the gas cap area and modify the area around the seam that joins the top and underside stampings to make a more 'composite production-friendly' shape - more on this later in the project.
2. Once I have a shape I like, I'll make what's called a 'splash mold' (a non-production quality mold) of the top and the underside.
3. I'll use the splash molds to make fiberglass-only parts that will be bonded together to make what's essentially a fiberlass replica of the stock tank.
4. Zoran, an experienced crasher of SVs, has proven that the sides of the stock SV tank stick out too far and are very susceptible to damage - see attached pics of the fabulous donor tank he's provided me as the starting point... So, I'm going to modify the fiberglass replica and narrow it as a pre-emtive design modification to combat the literal impact that might occur when one combines gravity and asphalt.
Note: Carbon fiber won't dent, it'll crack and break and splinter and grind away to dust if you impact it (with enough force) or drag it across a rough surface. It's not impact resistant. That's what the Kevlar is for.
4. Once these mods are all done (lots of bondo, popsicle sticks, and hot glue!) I'll have a model of the final shape I want. This is called the 'plug'. And now it's time to sand, sand, sand to get the finish as close to perfect as possible.
5. Once the plug is finished, I use it to make the production molds. It will likely be a three piece mold: a two-part top is needed if there are any combined surface angles that would cause what's called 'mold lock'. Think of making a mold using a lightbulb - you couldn't get it out of the mold unless the mold could be split. So the top will utilize a 'splitter plate'. I'll need to make one in order to make the splash mold so you'll see one of those soon enough...
6. Finally, once I have the production mold, I can layup the parts and make the tank. Or should I say tanks!
7. I may decide to make these available to others, we'll see. Depends on demand, how labor intensive they turn out to be, etc.
Zoran will likely not be greeted by a large, lightweight Christmas gift but I'll work on it as time permits.
So, stay tuned and feel free to contact me with questions, comments, etc.
Chris Baker
chris.b.baker@kp.org
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