foam problem

[Dave Lyon]

Sorry if this is a duplicate. I just went to check my last post, and it said
it was no longer available on the server. ?


Hey guys, I've been lurking around here for quite a while to get an
education. I'm building a project that could use a little expert guidance.

I am making a paintball tank. Not the type that you put air in, but the type
that you put people in. :) This is my 2nd tank. I used plywood for the skin
of my first one. It was very heavy, and it didn't look very good. So, I've
decided to do a fiberglass over foam body on this one.

I'm not worried about weight as much as I am strength and cost. Hopefully
this thing doesn't fly when I'm done. :) I went to the lumber yard and
bought some 1/2" polyisocyanurate foam insulation. I removed the paper from
both sides, and put 1 layer of 10 ounce woven glass on each side using
polyester resin that I got from Wal-Mart. I just made a small piece (about 1
foot square) for testing.

I was very pleased with the weight of the product, and the look that it
would give my tank, so I took it out back, and shot it with my paintball
gun. The first shot went great. The stuff is much stronger than it looks.
But, if you pelt it a number of times in the same spot, the foam crushed and
caused delaminating. :(

Now, on to the questions. If I ad more layers, will it be able to withstand
the beating I want to give it? How many layers do you think I'll need? I
ordered some Vinyl Ester resin from aircraft spruce. Will this hold up
better? I've got somebody to donate some fiberglass mat. Would it be OK to
use this under the cloth for more strength? Obviously I'm trying to keep the
cost down. Any recommendations would be greatly appreciated.

Dave

[Evan Carew]

Dave Lyon wrote:
> Sorry if this is a duplicate. I just went to check my last post, and it said
> it was no longer available on the server. ?
>
>
> Hey guys, I've been lurking around here for quite a while to get an
> education. I'm building a project that could use a little expert guidance.
>
> I am making a paintball tank. Not the type that you put air in, but the type
> that you put people in. :) This is my 2nd tank. I used plywood for the skin
> of my first one. It was very heavy, and it didn't look very good. So, I've
> decided to do a fiberglass over foam body on this one.
>
> I'm not worried about weight as much as I am strength and cost. Hopefully
> this thing doesn't fly when I'm done. :) I went to the lumber yard and
> bought some 1/2" polyisocyanurate foam insulation. I removed the paper from
> both sides, and put 1 layer of 10 ounce woven glass on each side using
> polyester resin that I got from Wal-Mart. I just made a small piece (about 1
> foot square) for testing.
Well, if you're concerned about cost, this won't exactly be cheap.
>
> I was very pleased with the weight of the product, and the look that it
> would give my tank, so I took it out back, and shot it with my paintball
> gun. The first shot went great. The stuff is much stronger than it looks.
> But, if you pelt it a number of times in the same spot, the foam crushed and
> caused delaminating. :(
Well, for aircraft purposes, we use much stronger foam than the
insulating variety. the "blue" foam, which is called Divinycell & is
made from open cell PVC is usually used by us for wings in the 1/4"
thickness. In order to use it, you need to coat it with a thin coating
of micro (microbolunes mixed with epoxy resin). This application is
quite rigid and light, tho it will delam with repeated hits by anything
solid.

For a sturdier foam/fiberglass combo, try the polyurethane foam called
"Last - A - Foam". This foam, sometimes used where weight is less of a
concern, but dimensional stability is, can be used as discussed above.

In both cases, the use of two layers of glass is typically enough to
prevent most physical trauma from causing delaminations. More than two
would probably only add weight with quickly diminishing returns on strength.
>
> Now, on to the questions. If I ad more layers, will it be able to withstand
> the beating I want to give it? How many layers do you think I'll need? I
> ordered some Vinyl Ester resin from aircraft spruce. Will this hold up
> better? I've got somebody to donate some fiberglass mat. Would it be OK to
> use this under the cloth for more strength? Obviously I'm trying to keep the
> cost down. Any recommendations would be greatly appreciated.
>
> Dave
>
>
>

[John T[_1_]]

You'll want to avoid using polyester resins on your foam, unless you
want your tank to melt! :)

I can see how this would be a problem. The foam would crush on impact
with a paintball, the fiberglass would eventually fail from the
dissortion of the foam underneath it.

maybe you could bond some aluminium skin to the foam. It'll dent like
crazy, but it might last longer!

[Dave Lyon]

"John T" > wrote in message
...
> You'll want to avoid using polyester resins on your foam, unless you
> want your tank to melt! :)

I tried various foams before I found this one. It didn't melt, but I wonder
if I got the best adhesion possible.

>
> I can see how this would be a problem. The foam would crush on impact
> with a paintball, the fiberglass would eventually fail from the
> dissortion of the foam underneath it.

Yea, I think that's what happended. The first couple of shots looked good,
but after a few dozen, things started to get messy. :)


>
> maybe you could bond some aluminium skin to the foam. It'll dent like
> crazy, but it might last longer!
>

I'd have to wear ear plugs to drive it! Have you ever been in a metal
building during a hail storm? :)

[Evan Carew]

John T wrote:
> You'll want to avoid using polyester resins on your foam, unless you
> want your tank to melt! :)
>
> I can see how this would be a problem. The foam would crush on impact
> with a paintball, the fiberglass would eventually fail from the
> dissortion of the foam underneath it.
>
> maybe you could bond some aluminium skin to the foam. It'll dent like
> crazy, but it might last longer!
>
Actually, the s-glass embedded in epoxy will perform better than the
aluminum. Thus the name "composite". You are combining a product, glass,
with a high tensile strength with something that has poor tensile
strength, epoxy. Then you bond that to something that has a high degree
of stiffness (foam). The idea is that when yo
u try to deform the foam/fiberglass composite, the high tensile strength
covering tries to distribute its load out over the foam. The higher the
tensile strength coating, the larger the area of load distribution.

[Dave Lyon]

"Evan Carew" > wrote in message
...
> John T wrote:
> > You'll want to avoid using polyester resins on your foam, unless you
> > want your tank to melt! :)
> >
> > I can see how this would be a problem. The foam would crush on impact
> > with a paintball, the fiberglass would eventually fail from the
> > dissortion of the foam underneath it.
> >
> > maybe you could bond some aluminium skin to the foam. It'll dent like
> > crazy, but it might last longer!
> >
> Actually, the s-glass embedded in epoxy will perform better than the
> aluminum. Thus the name "composite". You are combining a product, glass,
> with a high tensile strength with something that has poor tensile
> strength, epoxy. Then you bond that to something that has a high degree
> of stiffness (foam). The idea is that when yo
> u try to deform the foam/fiberglass composite, the high tensile strength
> covering tries to distribute its load out over the foam. The higher the
> tensile strength coating, the larger the area of load distribution.

So, you're saying that another layer of 10 oz glass will help my problem.

Can I put both layers on at one time and expect them to get wetted out
properly, or should I do them one at a time with a sanding step in-between?

[Evan Carew]

Dave Lyon wrote:
> "Evan Carew" > wrote in message
> ...
>
>>John T wrote:
>>
>>>You'll want to avoid using polyester resins on your foam, unless you
>>>want your tank to melt! :)
>>>
>>>I can see how this would be a problem. The foam would crush on impact
>>>with a paintball, the fiberglass would eventually fail from the
>>>dissortion of the foam underneath it.
>>>
>>>maybe you could bond some aluminium skin to the foam. It'll dent like
>>>crazy, but it might last longer!
>>>
>>
>>Actually, the s-glass embedded in epoxy will perform better than the
>>aluminum. Thus the name "composite". You are combining a product, glass,
>>with a high tensile strength with something that has poor tensile
>>strength, epoxy. Then you bond that to something that has a high degree
>>of stiffness (foam). The idea is that when yo
>>u try to deform the foam/fiberglass composite, the high tensile strength
>>covering tries to distribute its load out over the foam. The higher the
>>tensile strength coating, the larger the area of load distribution.
>
>
> So, you're saying that another layer of 10 oz glass will help my problem.
>
> Can I put both layers on at one time and expect them to get wetted out
> properly, or should I do them one at a time with a sanding step in-between?
>
>
Typically, you would put them on at the same time. What you do when you
are doing wet layup on raw foam is to squeegee a film of micro onto the
foam first. This will act as the binder between your fiberglass & your
foam. Then, get a long cardboard tube, just longer than the width of
your glass cloth bolt. Then, cut two lengths of glass to size and roll
then up (stacked evenly ontop of each other) onto the tube. Now, unroll
the dry glass onto the foam where you squeegeed the wet micro. Finally,
use a paint brush with stiff bristles to "stipple" the epoxy into the
two layers of glass. When you are happy there are no subsurface voids,
take your squeegy and squeeze out any extra epoxy (adds weight but no
strength). That's the way the book says to do it. I just use the squeegy
tho and work the epoxy back and forth until all the cloth is wet. This
technique works well up to 4 layers thick.

In the event that you need local reinforcement for a physical attachment
(bolt your panels to a frame), you will need to embed hard-points. THis
is done by getting a square of spare plywood the same thickness of your
foam, then cutting out the same sized square in the foam prior to
glassing. Its ok to use a hot glue gun to fix the plywood in place for
easy handling. As for the rest, well, you get the idea.

[Dave Lyon]

"Evan Carew" > wrote in message
t...
> Dave Lyon wrote:
> > "Evan Carew" > wrote in message
> > ...
> >
> >>John T wrote:
> >>
> >>>You'll want to avoid using polyester resins on your foam, unless you
> >>>want your tank to melt! :)
> >>>
> >>>I can see how this would be a problem. The foam would crush on impact
> >>>with a paintball, the fiberglass would eventually fail from the
> >>>dissortion of the foam underneath it.
> >>>
> >>>maybe you could bond some aluminium skin to the foam. It'll dent like
> >>>crazy, but it might last longer!
> >>>
> >>
> >>Actually, the s-glass embedded in epoxy will perform better than the
> >>aluminum. Thus the name "composite". You are combining a product, glass,
> >>with a high tensile strength with something that has poor tensile
> >>strength, epoxy. Then you bond that to something that has a high degree
> >>of stiffness (foam). The idea is that when yo
> >>u try to deform the foam/fiberglass composite, the high tensile strength
> >>covering tries to distribute its load out over the foam. The higher the
> >>tensile strength coating, the larger the area of load distribution.
> >
> >
> > So, you're saying that another layer of 10 oz glass will help my
problem.
> >
> > Can I put both layers on at one time and expect them to get wetted out
> > properly, or should I do them one at a time with a sanding step
in-between?
> >
> >
> Typically, you would put them on at the same time. What you do when you
> are doing wet layup on raw foam is to squeegee a film of micro onto the
> foam first. This will act as the binder between your fiberglass & your
> foam.

Oh, I didn't do that. How thick do I want to make it? How much/many
microspheres are needed to do a square foot?


Then, get a long cardboard tube, just longer than the width of
> your glass cloth bolt. Then, cut two lengths of glass to size and roll
> then up (stacked evenly ontop of each other) onto the tube. Now, unroll
> the dry glass onto the foam where you squeegeed the wet micro. Finally,
> use a paint brush with stiff bristles to "stipple" the epoxy into the
> two layers of glass. When you are happy there are no subsurface voids,
> take your squeegy and squeeze out any extra epoxy (adds weight but no
> strength). That's the way the book says to do it. I just use the squeegy
> tho and work the epoxy back and forth until all the cloth is wet. This
> technique works well up to 4 layers thick.

Thanks! that's the info I needed.
I assume I need to work in small enough patches so that I can get all the
glass on before the micro level dries. And, I should overlap the ends of the
mat a bit. Can I come back and use microbeads to fillet the small step that
the glass leaves on my overlaps, or is it better to use bondo? Remember,
weight is not my enemy, price is.

>
> In the event that you need local reinforcement for a physical attachment
> (bolt your panels to a frame), you will need to embed hard-points. THis
> is done by getting a square of spare plywood the same thickness of your
> foam, then cutting out the same sized square in the foam prior to
> glassing. Its ok to use a hot glue gun to fix the plywood in place for
> easy handling. As for the rest, well, you get the idea.

In my case, I built a steel frame around my tank so I would have something
to hold my foam in place. My thought was to add the 1/2 foam to the outside
of the frame, holding it in place with hot glue and duct tape. Then, I would
fiberglass over the whole thing. I'd cut a hole in the top where the turret
goes, so I can climb into the inside and glass it. I used 1" square tube for
the frame. I hadn't decided if I would cut some tapered foam for the inside
to bevel from the 1" step back to the foam before glassing, or if I would
just fill the complete void with more foam. The later would give me a nice
smooth surface on the inside, but it would obviously cost me more in foam.

When I get all the foam on both sides, I was going to cut the doors and
windows out. I would glass up some stops, and attach the doors back on with
some hinges.

[Evan Carew]

Dave Lyon wrote:
> "Evan Carew" > wrote in message
> t...
>
>>Dave Lyon wrote:
>>
>>>"Evan Carew" > wrote in message
...
>>>
>>>
>>>>John T wrote:
>>>>
>>>>
>>>>>You'll want to avoid using polyester resins on your foam, unless you
>>>>>want your tank to melt! :)
>>>>>
>>>>>I can see how this would be a problem. The foam would crush on impact
>>>>>with a paintball, the fiberglass would eventually fail from the
>>>>>dissortion of the foam underneath it.
>>>>>
>>>>>maybe you could bond some aluminium skin to the foam. It'll dent like
>>>>>crazy, but it might last longer!
>>>>>
>>>>
>>>>Actually, the s-glass embedded in epoxy will perform better than the
>>>>aluminum. Thus the name "composite". You are combining a product, glass,
>>>>with a high tensile strength with something that has poor tensile
>>>>strength, epoxy. Then you bond that to something that has a high degree
>>>>of stiffness (foam). The idea is that when yo
>>>>u try to deform the foam/fiberglass composite, the high tensile strength
>>>>covering tries to distribute its load out over the foam. The higher the
>>>>tensile strength coating, the larger the area of load distribution.
>>>
>>>
>>>So, you're saying that another layer of 10 oz glass will help my
>
> problem.
>
>>>Can I put both layers on at one time and expect them to get wetted out
>>>properly, or should I do them one at a time with a sanding step
>
> in-between?
>
>>>
>>Typically, you would put them on at the same time. What you do when you
>>are doing wet layup on raw foam is to squeegee a film of micro onto the
>>foam first. This will act as the binder between your fiberglass & your
>>foam.
>
>
> Oh, I didn't do that. How thick do I want to make it? How much/many
> microspheres are needed to do a square foot?
You don't actually count them, they are ~20 microns in diameter. What
you do is purchase a bag of them from aircraft spruce (cheap). Make your
epoxy mixture, then start pouring in microspheres until you have a
slurry resembling thinnish peanut butter. Note, the color is a near match.
>
>
> Then, get a long cardboard tube, just longer than the width of
>
>>your glass cloth bolt. Then, cut two lengths of glass to size and roll
>>then up (stacked evenly ontop of each other) onto the tube. Now, unroll
>>the dry glass onto the foam where you squeegeed the wet micro. Finally,
>>use a paint brush with stiff bristles to "stipple" the epoxy into the
>>two layers of glass. When you are happy there are no subsurface voids,
>>take your squeegy and squeeze out any extra epoxy (adds weight but no
>>strength). That's the way the book says to do it. I just use the squeegy
>>tho and work the epoxy back and forth until all the cloth is wet. This
>>technique works well up to 4 layers thick.
>
>
> Thanks! that's the info I needed.
> I assume I need to work in small enough patches so that I can get all the
> glass on before the micro level dries. And, I should overlap the ends of the
> mat a bit. Can I come back and use microbeads to fillet the small step that
> the glass leaves on my overlaps, or is it better to use bondo? Remember,
> weight is not my enemy, price is.
Hmm. Ok, well, I have seen guys lay on squares of ~1yard. The micro (in
epoxy) and your plain epoxy for potting the glass cloth have ~45min of
useful spreading life (read the instructions as your brand may differ).
During this time, you can spread to your hearts content, so use your
progress on a test square to gage the maximum amount of yardage you can
do at a time. As for overlap, yes, that's ok. Generally, you want 2
inches of overlap. If the previous patch of fiberglass is still tacky,
go ahead and lay ontop of it. If cured, sand and clean, then proceed.
>
>
>>In the event that you need local reinforcement for a physical attachment
>>(bolt your panels to a frame), you will need to embed hard-points. THis
>>is done by getting a square of spare plywood the same thickness of your
>>foam, then cutting out the same sized square in the foam prior to
>>glassing. Its ok to use a hot glue gun to fix the plywood in place for
>>easy handling. As for the rest, well, you get the idea.
>
>
> In my case, I built a steel frame around my tank so I would have something
> to hold my foam in place. My thought was to add the 1/2 foam to the outside
> of the frame, holding it in place with hot glue and duct tape. Then, I would
> fiberglass over the whole thing. I'd cut a hole in the top where the turret
> goes, so I can climb into the inside and glass it. I used 1" square tube for
> the frame. I hadn't decided if I would cut some tapered foam for the inside
> to bevel from the 1" step back to the foam before glassing, or if I would
> just fill the complete void with more foam. The later would give me a nice
> smooth surface on the inside, but it would obviously cost me more in foam.
>
> When I get all the foam on both sides, I was going to cut the doors and
> windows out. I would glass up some stops, and attach the doors back on with
> some hinges.
>
>
Don't forget, laying glass & spreading epoxy while fighting gravity is
messy business. If you can work it. Always try to figure out how to get
your work surface mostly horizontal.

[Dave Lyon]

> > Oh, I didn't do that. How thick do I want to make it? How much/many
> > microspheres are needed to do a square foot?
> You don't actually count them, they are ~20 microns in diameter. What
> you do is purchase a bag of them from aircraft spruce (cheap). Make your
> epoxy mixture, then start pouring in microspheres until you have a
> slurry resembling thinnish peanut butter. Note, the color is a near match.

Yea, that's what I thought. I was just trying to figure out how much I
should order.


> Don't forget, laying glass & spreading epoxy while fighting gravity is
> messy business. If you can work it. Always try to figure out how to get
> your work surface mostly horizontal.

I wondered about that. I've got a fork lift. Maybe I should weld some tow
hooks all around this thing so I can spin it.

[Evan Carew]

Dave Lyon wrote:
>>>Oh, I didn't do that. How thick do I want to make it? How much/many
>>>microspheres are needed to do a square foot?
>>
>>You don't actually count them, they are ~20 microns in diameter. What
>>you do is purchase a bag of them from aircraft spruce (cheap). Make your
>>epoxy mixture, then start pouring in microspheres until you have a
>>slurry resembling thinnish peanut butter. Note, the color is a near match.
>
>
> Yea, that's what I thought. I was just trying to figure out how much I
> should order.
>
>
>
>>Don't forget, laying glass & spreading epoxy while fighting gravity is
>>messy business. If you can work it. Always try to figure out how to get
>>your work surface mostly horizontal.
>
>
> I wondered about that. I've got a fork lift. Maybe I should weld some tow
> hooks all around this thing so I can spin it.
>
>
As a matter of fat, that's what we do with our aircraft. Or, you can
make your layups on plastic bags on the floor, then apply them like they
were sticky wall paper. After the layup has been applied, peel off the
plastic bag.

[Dave Lyon]

>
> Another ply on the outside will help, but eventually it will get too
> heavy.
>
> I'd go the other way. Skin the outside with 1/" wetsuit neoprene.

Really? Don't tease me, I'm an easy target. It's like making fun of Jerry's
kids (Lewis, not Springer) , it just really should be done.

Anybody know where I can get some camo neoprene for cheap? :)

[Montblack[_1_]]

("Dave Lyon" wrote)
> Really? Don't tease me, I'm an easy target. It's like making fun of
> Jerry's kids (Lewis, not Springer) , it just really should be done.
>
> Anybody know where I can get some camo neoprene for cheap? :)


Unless I missed it, can you give us some more details on this project? Some
history. Some past failures of prototypes. <g>

Possible size?
Number of people inside?

Weapons against it (mass, speed, penetrating power, rate-of-fire, etc?)

Budget?

Mission?
Special functions to incorporate into unit?

Tanks... :-)


Montblack-ops

[Tim Ward[_1_]]

"Dave Lyon" > wrote in message
news:avNCg.84182$FQ1.83676@attbi_s71...
>
> >
> > Another ply on the outside will help, but eventually it will get too
> > heavy.
> >
> > I'd go the other way. Skin the outside with 1/" wetsuit neoprene.
>
> Really? Don't tease me, I'm an easy target. It's like making fun of
Jerry's
> kids (Lewis, not Springer) , it just really should be done.
>
> Anybody know where I can get some camo neoprene for cheap? :)

A slightly different solution, that may add more weight , but might be
cheaper than the denser foam:
Skin the outside with lauan doorskins. They're pretty cheap, and it should
spread the load so that the paintballs don't ding the foam.
You might consider making another test panel of fiberglass inside, foam
core, and just the doorskin outside, or a lighter-weight fiberglass cloth on
the outside.

From a cost point of view, I suspect that door skin/foam/doorskin sandwich
glued with urethane glue will be cheaper than fiberglass. I don't know what
thickness plywood you were using before, but this should have the stiffness
of 3/4 inch plywood with about a third the weight. A thicker core will
increase the stiffness without affecting the weight very much.

Tim Ward

[Evan Carew]

Tim Ward wrote:
> "Dave Lyon" > wrote in message
> news:avNCg.84182$FQ1.83676@attbi_s71...
>
>>>Another ply on the outside will help, but eventually it will get too
>>>heavy.
>>>
>>>I'd go the other way. Skin the outside with 1/" wetsuit neoprene.
>>
>>Really? Don't tease me, I'm an easy target. It's like making fun of
>
> Jerry's
>
>>kids (Lewis, not Springer) , it just really should be done.
>>
>>Anybody know where I can get some camo neoprene for cheap? :)
>
>
> A slightly different solution, that may add more weight , but might be
> cheaper than the denser foam:
> Skin the outside with lauan doorskins. They're pretty cheap, and it should
> spread the load so that the paintballs don't ding the foam.
> You might consider making another test panel of fiberglass inside, foam
> core, and just the doorskin outside, or a lighter-weight fiberglass cloth on
> the outside.
>
> From a cost point of view, I suspect that door skin/foam/doorskin sandwich
> glued with urethane glue will be cheaper than fiberglass. I don't know what
> thickness plywood you were using before, but this should have the stiffness
> of 3/4 inch plywood with about a third the weight. A thicker core will
> increase the stiffness without affecting the weight very much.
>
> Tim Ward
>
>
The luan will eventually dent and break just like a single ply of
fiberglass on weak foam. I know, I play with paintball guns too ;)

Evan

[Dave Lyon]

"Montblack" > wrote in message
...
> ("Dave Lyon" wrote)
> > Really? Don't tease me, I'm an easy target. It's like making fun of
> > Jerry's kids (Lewis, not Springer) , it just really should be done.
> >
> > Anybody know where I can get some camo neoprene for cheap? :)
>
>
> Unless I missed it, can you give us some more details on this project?
Some
> history. Some past failures of prototypes. <g>
>
> Possible size?
> Number of people inside?
>
> Weapons against it (mass, speed, penetrating power, rate-of-fire, etc?)
>
> Budget?
>
> Mission?
> Special functions to incorporate into unit?
>
> Tanks... :-)
>
>
> Montblack-ops
>

How much history?

.....In the beginning....... :)

I've been into paintball for a few years. Probably as long as some of you
have been trying to get your planes built. :)
About 3 years ago, I built a tank for use at a big paintball event that
takes place each year in OK. They call it D-day, and try to get it as close
to June 6th as they can. The last time I went, there were over 3000 players,
and probably around 12 tanks. Most people make their tanks from 4 wheel
drive trucks. I decided that was too easy, so I pieced mine together from
scratch using plywood for the outside. There is a 5 mph speed limit for
tanks so kids don't get run over, so I used mostly lawn mower parts. It
sported a 3" main gun that would shoot 90 paintballs at a time like a shot
gun. Those cannot be used against people, only other tanks. At d-day, the
put a small box on the outside of the tank that hides a switch. There is a
1" hole in the box. If you can shoot a paintball inside the box, and hit the
switch, it disconnects the coil wire, and the tank is dead. The job is much
harder than you might think, cause while you're trying to hit that little
target, there are at least 2 guys inside the tank blasting away at you!.
Also, you can take out a tank with a "bazooka". Most of them are homemade
kinda like a potato launcher. They usually have a 2" pvc barrel, and shoot
miniature nerf footballs at 220 fps. Or, paintballs are allowed to be shot
at 300 fps.

I sold my old tank, and decided to build one that looks more realistic. I
started it over a year ago, but got busy on other stuff, so it just sat in
storage for quite a while The new one is modeled after a m1117 guardian, and
will look quite a bit like it. It will be about 14 feet long, and have a
crew of 3 people. A driver, a main gunner, and a crewman. My new tank will
serve a dual role. I have purchased some high end M.I.L.E.S. type gear, and
have been hosting birthday parties for people. The first turret I put on
there will be equipped with similar gear to replicate a 50 cal, and
automatic grenade launcher. I will use it as a promotional item in parades
and such, and also rent it out for private parties. I figure when I'm done
with the first one, I can build a new turret for paintball use, and hit some
of those big events too.

I've done a few more experimental lay ups. I've found that 2 layers of 10 oz
cloth is very strong. It may do the trick. I hit my small sample from 10
feet away with about 30 shots. It delaminated when it hit near the edges,
but not in the middle of the part. Since the tank won't actually have any
"edges", I think it may be ok. I think I'm going to finish the tank with 2
layers (3 if I have enough extra). Then I'll take a few shots in an easy to
repair area and see what happens. Besides, the actual tank doesn't have any
flat areas, everything is at an angle to deflect incoming shots hopefully
that helps some too. :)

[Dave Lyon]

"Richard Riley" > wrote in message
...
> On Thu, 10 Aug 2006 21:25:26 GMT, "Dave Lyon" >
> wrote:
>
> >
> >>
> >> Another ply on the outside will help, but eventually it will get too
> >> heavy.
> >>
> >> I'd go the other way. Skin the outside with 1/" wetsuit neoprene.
> >
> >Really? Don't tease me, I'm an easy target. It's like making fun of
Jerry's
> >kids (Lewis, not Springer) , it just really should be done.
> >
> >Anybody know where I can get some camo neoprene for cheap? :)
> >
>
> Sorry, that should have been 1/4" neoprene.
>
> Just do a google search on it, there are LOTS of suppliers. The first
> one I found was http://www.foamorder.com/neoprene.html
>
> If you were going to be REALLY creative and cheap, you'd contact a wet
> suit manufacturer and offer to haul away their scraps. Then jigsaw it
> together all over your tank, paint it cammo with spray cans. Glue it
> to the fiberglass with spray on trim adhesive.

Honestly, I thought you were teasing about the neoprene. But, I did a google
search, and not only did I find it in Camo, but I also found it with velcro
attached to the back. I think I'm going to make the body fiberglass with at
least 2 layers on the outside. Then I'll do some testing in an easy to
repair area. If it holds up, then I'm in good shape. If not, I may look at
making a "glove" for paintball use. :)