Radon photos

[carl correll]

What a brilliant design. It's a tube frame for sure. The fasteners are six inches apart and I presume not bonded to the frame.

Reminds me of Bruns noticing that his "tub" had to contain a specified number of square inches of volume per side. Dimensions were not specified, nor was the manner in which the "body" was to be affixed. 1 inch thick aluminum honeycomb had two aluminum skins, and when properly folded produced the required volume of "tub". In fact, the top of the "body" had two strips of fiberglass screwed on behind the windscreen. I figured it would look cooler to replace those with matching windscreen material. "Can't do that". "Why?" "Because they form the cockpit opening width and without them the opening is too small".

Thank God the internet was yet to be.

[Rennie Clayton]

The GCR does actually consider every other type of material. Covered in the first four sentences of the FC section.

What is the essential quality or property that makes the carbon panel in question structural?


Cheers,
Rennie

[Wren]

What is the essential quality or property that makes the carbon panel in question structural?

Nathan says so.

[Rennie Clayton]

Nathan says so.

Nathan says a lot of other stuff that you disagree with, why choose this one to be in agreement with?

What, per the GCR, is the essential quality or property that makes these panels structural?


Cheers,
Rennie

[Wren]

Nathan says a lot of other stuff that you disagree with, why choose this one to be in agreement with?

What, per the GCR, is the essential quality or property that makes these panels structural?

You and I both know that the GCR doesn't address these panels, so they are not allowed. That is the most important concept of a restricted class.

[Rennie Clayton]

You and I both know that the GCR doesn't address these panels, so they are not allowed. That is the most important concept of a restricted class.

Wren,

I really would prefer it if you let me characterize my own opinions, thanks. I do not "know" that they are not allowed. As it happens, I don't see anything torturous about the notion that the panels in question are within the space that contains the driver - and therefore explicitly permitted. The only question is whether they are past the threshold for "structural" as established by a GCR-based litmus test.

I am still curious to know; what is the essential quality or property that makes these panels structural?


Cheers,
Rennie

[Wren]

Wren,

I really would prefer it if you let me characterize my own opinions, thanks. I do not "know" that they are not allowed.

Sorry, I just meant to say that there is nothing within the FC rules that addresses these panels.

I am still curious to know; what is the essential quality or property that makes these panels structural?

Nothing, there is nothing there to cover these panels, as they will be a new way of constructing cars. The lack of rules covering them would also probably explain why Nathan would like to help write new rules for the construction of these cars, they are outside of the current rules.

Somehow I doubt that anyone would be ok with me attaching giant carbon sheets to the outside of my DB6 with cherrymax rivets just like I would attach a floor, but people would be ok with me pulling several rivets close together to attach a carbon sheet to hold my radio.

On another note, what will the bellhousing of this car be made out of? CF? Al? Mg?

[S Lathrop]

Wren,

I really would prefer it if you let me characterize my own opinions, thanks. I do not "know" that they are not allowed. As it happens, I don't see anything torturous about the notion that the panels in question are within the space that contains the driver - and therefore explicitly permitted. The only question is whether they are past the threshold for "structural" as established by a GCR-based litmus test.

I am still curious to know; what is the essential quality or property that makes these panels structural?


Cheers,
Rennie

I think Nathan answered that question. If the car won't work without them, then I would assume that they are structural and/or stress bearing. But they are not a part of the frame as a removable brace might be. Remember they are fastened in a non-stress bearing maner. We have something that suppliments the strength of the frame but doen't? Given time I might be able to understand the logic here.

[Daryl DeArman]

Remember they are fastened in a non-stress bearing maner. We have something that suppliments the strength of the frame but doen't? Given time I might be able to understand the logic here.

Certainly they supplement the strength of the frame, but not in a manner prohibited by the GCR. That's the logic. Really simple to understand IF you don't have a vested interest in how the rule is interpreted.

[Wren]

Certainly they supplement the strength of the frame, but not in a manner prohibited by the GCR. That's the logic. Really simple to understand IF you don't have a vested interest in how the rule is interpreted.

It isn't about what is prohibited, it is about what is allowed. It is a restricted class. I have no financial interest in the interpretation.

[Rennie Clayton]

Sorry, I just meant to say that there is nothing within the FC rules that addresses these panels.

Sure there is; they are panels within the space that contains the driver, explicitly allowed (in carbon) per the GCR.

Somehow I doubt that anyone would be ok with me attaching giant carbon sheets to the outside of my DB6 with cherrymax rivets just like I would attach a floor, but people would be ok with me pulling several rivets close together to attach a carbon sheet to hold my radio.

Neither of those two scenarios is in question.

I think Nathan answered that question. If the car won't work without them, then I would assume that they are structural and/or stress bearing. But they are not a part of the frame as a removable brace might be. Remember they are fastened in a non-stress bearing maner. We have something that suppliments the strength of the frame but doen't? Given time I might be able to understand the logic here.

Well, how do you reconcile that dichotomy if the Radon panels were aluminum or steel, and anchored on 6.01" centers? They are clearly supplementing the strength of the frame, yes? But they would be letter-perfect legal per the rules.

The closest I see to a litmus test for "stress-bearing" in the GCR, regardless of material in use, is the 6" center attachment provision. It seems to me that you agree with the 6" center as being a rational litmus test for stress bearing panels, given your statement above (in bold). That being the case, these panels (as I understand them) do not fit the criteria for stress-bearing.


Cheers,
Rennie

[Mike Foschi]

Certainly they supplement the strength of the frame, but not in a manner prohibited by the GCR. That's the logic. Really simple to understand IF you don't have a vested interest in how the rule is interpreted.

Once again, I have no vested interest.
The rule was written all those years ago to NOT allow the strenghtening of the tube frame by any means. I think that rule came about because of the early super v's were playing with the idea, I could be wrong. Just because newer materials are available does not change the INTENT of the rule that does not want there to be strenghtening of the tube frame.
Now that Nathen has stated for all of us to see that the panel does indeed strenghten the frame I would figure that the SCCA would deem it "not confirming to the intent of the rules".
As far as making the cars safer, who dosen't want that? There are probably a hundred ways of making anti intrusion panels without having to design a new car. For all of you that wants a new, safer from the ground up, open wheel car start a new class that has a carbon tub and large crushable structure side pods instead of hi jacking a popular class that needs no help in destoying itself from the inside out.

[S Lathrop]

Certainly they supplement the strength of the frame, but not in a manner prohibited by the GCR. That's the logic. Really simple to understand IF you don't have a vested interest in how the rule is interpreted.

And Nathan and his investors don't? Some what narrowed minded on your part.

[S Lathrop]

Sure there is; they are panels within the space that contains the driver, explicitly allowed (in carbon) per the GCR.




Neither of those two scenarios is in question.




Well, how do you reconcile that dichotomy if the Radon panels were aluminum or steel, and anchored on 6.01" centers? They are clearly supplementing the strength of the frame, yes? But they would be letter-perfect legal per the rules.

The closest I see to a litmus test for "stress-bearing" in the GCR, regardless of material in use, is the 6" center attachment provision. It seems to me that you agree with the 6" center as being a rational litmus test for stress bearing panels, given your statement above (in bold). That being the case, these panels (as I understand them) do not fit the criteria for stress-bearing.


Cheers,
Rennie

Read your father's post carefully.

[Rennie Clayton]

Read your father's post carefully.

Steve,

If there is something specific you'd like to point out, you are free to do so without cryptic references. I've read his post. What, in particular, strikes you as relevant to establishing what is a stress-bearing panel per the current GCR?

What is the essential quality or property that makes these panels structural?


Cheers,
Rennie

[S Lathrop]

Steve,


What is the essential quality or property that makes these panels structural?


Cheers,
Rennie

Nathan's statement that the car won't work without the panels in place.

[ric baribeault]

i know i said i wouldn't post again on this as i have mixed emotions on it akin to the ex-wife driving off a cliff in my brand new ferrari. BUT, it seems that after 11 pages of everything from posts bordering personal attacks, to some actually informative and thoughtful responses, we're back to square 1. apparently legal by the letter of the law and minimally questionable at best as to the intent of the rules. this really won't be decided by us so what was the point?

[S Lathrop]

i know i said i wouldn't post again on this as i have mixed emotions on it akin to the ex-wife driving off a cliff in my brand new ferrari. BUT, it seems that after 11 pages of everything from posts bordering personal attacks, to some actually informative and thoughtful responses, we're back to square 1. apparently legal by the letter of the law and minimally questionable at best as to the intent of the rules. this really won't be decided by us so what was the point?

Amen.

[Rennie Clayton]

Nathan's statement that the car won't work without the panels inplace.

Let me direct you to what Nathan actually said:

Really? What makes you think that? If I take the cockpit protection panels off, the car will roll just fine.

"Works", it would appear, is a somewhat subjective threshold.

Either way, "works" is not a criteria in the GCR for establishing whether a given panel is stess bearing. Which leads me right back to that essential quality or property, etc.


Cheers,
Rennie

[Mike Foschi]

Unfortunately, homologation provides no guarantee of legality in the SCCA, nor does it protect against rules changes.

I'm sorry, that's just not true. If you don't believe me, then ask any F1, F3, or Indycar designer why their cockpit survival cells use carbon fiber as the main structural component. Yes, they add additional materials, like Kevlar or Zylon, for their extreme tensile strength, but those materials are awful in compression.

We used a fiber called Innegra to provide penetration resistance. It's much lower cost than Kevlar or Zylon and has many of the same properties. You can see some patches of it on the outside of the panels (the whitish areas) but it's also used as core.

Also, have you priced carbon fiber fabric recently? The bulk of the panel is made from a very heavy cloth that is also quite inexpensive. With the RTM manufacturing process, the panels are very low cost.

I have never claimed these panels serve no structural purpose, in fact I have acknowledged it over and over again. That's one of the reasons they reduce the overall cost of the frame, since they eliminate many little tubes, gussets, and brackets.

Unlike FB, the FC rules allow carbon fiber interior panels and structural brackets. Bolted-together bell housings are a good example of a "bracket," without which the car can't even roll, let alone drive, yet are clearly in violation of the prohibition against stressed panels for chassis construction.

Nathan

Looks like acknowledgment to me. That's post #64

[S Lathrop]

Let me direct you to what Nathan actually said:



"Works", it would appear, is a somewhat subjective threshold.

Either way, "works" is not a criteria in the GCR for establishing whether a given panel is stess bearing. Which leads me right back to that essential quality or property, etc.


Cheers,
Rennie

If Nathan is willing to race the cars without the panels, I retract all my posts on this subject and I will stand vanquished.

[VehDyn]

Once again, I have no vested interest.
The rule was written all those years ago to NOT allow the strenghtening of the tube frame by any means. I think that rule came about because of the early super v's were playing with the idea, I could be wrong. Just because newer materials are available does not change the INTENT of the rule that does not want there to be strenghtening of the tube frame.
Now that Nathen has stated for all of us to see that the panel does indeed strenghten the frame I would figure that the SCCA would deem it "not confirming to the intent of the rules".
As far as making the cars safer, who dosen't want that? There are probably a hundred ways of making anti intrusion panels without having to design a new car. For all of you that wants a new, safer from the ground up, open wheel car start a new class that has a carbon tub and large crushable structure side pods instead of hi jacking a popular class that needs no help in destoying itself from the inside out.

These type of interpretations fall under the twisted, tortous interpretation of the rules. If the intent was to no structural panels, they would have said no structural panels. If the intent was to minimize the effect of structural panels, they would provide a direction to minimize the effect of structural panels. Oh wait, they did; the 6 inch center rule. Every panel, whether they are attached at 6, 6.1 or 8 inch centers will add some rigidity assuming the material is strong enough to overcome the attachment method. For this discussion lets leave paper and stuff like that off the table. Therefore, by allowing the the 6 inch center method, the rules makers have conceeded that its acceptable to have some strengthening and as far as I can see the argument about structural panels is off the table as it meets the letter with the attachment method.

The material likely will be something that will have to be explained.

The intent of the rules is only relevant in the brainstorming sessions prior to writing the rules. When they are in print, that is what designers must adhere to. How does a tech inspector under 50 enforce intent if they werent at the rules party?

[Wren]

Sure there is; they are panels within the space that contains the driver, explicitly allowed (in carbon) per the GCR.

The intent of that rule is not to allow huge carbon panels on the car.

Neither of those two scenarios is in question.

Actually yes it is. They are both legitimate results if people follow the tortuous logic applied here.

Well, how do you reconcile that dichotomy if the Radon panels were aluminum or steel, and anchored on 6.01" centers? They are clearly supplementing the strength of the frame, yes? But they would be letter-perfect legal per the rules.

Because that is specifically allowed in the rules. Carbon is specifically disallowed. The 6" rule is part of the frame rule, so if you want to apply it, then you have to apply the rest of the frame rules to that part, which ban carbon. The interior panel exception is in the bodywork rules.

How am I supposed to know which part of the frame rules we are going to apply and which parts we are not going to apply to each specific part? I can't wait to apply this same logic to the engine.

The closest I see to a litmus test for "stress-bearing" in the GCR, regardless of material in use, is the 6" center attachment provision.

Stretching some rules to cover something they don't allow is the exact opposite of a restricted class

[Mike Foschi]

Ok, I'm just saying what I think will happen to this car. We have not even started talking about the floor as of yet.

But, I'm done with this, there is only one thing more to do, and that's putting your money where your mouth, or fingers, is/are.

I propose we have a pool of money that we paypal to the Carters to hold to see who is correct in which way the SCCA will vote on this car. Lets say $20. each yes or no vote. The Carters get to keep a percentage of the total and the winners get to divide the rest. We all can afford $20. and we all could than let the Carters know that we appreciate the site.

[Rennie Clayton]

If Nathan is willing to race the cars without the panels, I retract all my posts on this subject and I will stand vanquished.

Ok, but this still doesn't establish the essential quality or property which makes the panels stress-bearing. His willingness to race the cars without the panels doesn't have any direct relation to their legality.

The intent of that rule is not to allow huge carbon panels on the car.

This is a torturous interpretation at best; nowhere in the relevant rules governing panels in the space containing the driver is there a restriction of any sort on panel size.

Because that is specifically allowed in the rules. Carbon is specifically disallowed. The 6" rule is part of the frame rule, so if you want to apply it, then you have to apply the rest of the frame rules to that part, which ban carbon. The interior panel exception is in the bodywork rules.

How am I supposed to know which part of the frame rules we are going to apply and which parts we are not going to apply to each specific part? I can't wait to apply this same logic to the engine.

Bodywork is attached to the frame; what governs its attachment guidelines?


Cheers,
Rennie

[S Lathrop]

Ok, I'm just saying what I think will happen to this car. We have not even started talking about the floor as of yet.

But, I'm done with this, there is only one thing more to do, and that's putting your money where your mouth, or fingers, is/are.

I propose we have a pool of money that we paypal to the Carters to hold to see who is correct in which way the SCCA will vote on this car. Lets say $20. each yes or no vote. The Carters get to keep a percentage of the total and the winners get to divide the rest. We all can afford $20. and we all could than let the Carters know that we appreciate the site.

This is the most reasonable post so far.

[nulrich]

Let me make this simple.

The panels serve a structural purpose.

The car will roll fine without them.

They do not meet the definition of "stress-bearing panel" in the GCR and are therefore not prohibited. The six-inch rule has been in place since at least 1985 and there has been no suggestion to change it until (supposedly coincidentally ) our car appeared.

There are many cars out there that have panels in their bolted-together bell housings that meet the definition of stress-bearing panels, are therefore specifically prohibited by the GCR, but are considered legal because they have been interpreted to be "brackets." Those cars will fall apart, and certainly won't roll or drive without those panels in place. That seems a much more tortuous interpretation of the GCR to me (but I think it's fine those cars are allowed).

I will say, once again, that we are perfectly happy to abide by the decision of the Court of Appeals on the legality of our car under the 2010 GCR.

Nathan

[LJennings]

So..........are you going to bring the car to the runoffs?

[Mike Foschi]

Nathan, a couple of quick easy questions for you.

1. When is the car supposed to be ready to view and run? I need to work on the pool.

2. I'm assuming your $20 will be on that it will be Ok'ed by the SCCA.

[nulrich]

In FIA FC-type tube frame chassis, anti-intrusion panels are permitted fewer attachment points than is permitted in SCCA. In FIA the panels are attached only at the four corners, plus once in the middle of the upper, lower, front and rear spans, and once in the middle of each diagonal tube. The number and type of attachment points are specified to minimize the strength the panels add to the chassis, while ensuring they remain in place during a collision. Moreover, FIA chassis must pass all their quasi-static and crash tests without the panels in place...only then are the panels added.

Since Dr. Ulrich is so keen to point out that his chassis incorporates many FIA safety standards, perhaps he can address whether it will pass the FIA's side intrusion test without the panels in place?

Hello Stan:

I'll have to review Appendix J again to understand the FIA requirements more thoroughly, but I'll answer your question right away.

I think it's unlikely that our car would pass the FIA side intrusion test without the cockpit protection panels in place. With them in place, I'm sure our car is safer than any other FF/FC car in existence.

Of course, the only FIA requirement for a FF/FC car in the GCR is the rollover protection required for "alternate" roll hoop designs (and it's an older FIA standard, in fact). Our car passes that easily, and is on the order of five to seven times stronger than the SCCA minimum WITHOUT the cockpit protection panels in place.

It might also be useful to point out that the 10 mm thick solid Dyneema panels specified in the FIA side-intrusion requirements would cost more than our entire chassis combined. Seems a little strange to only require .02" of Kevlar on every other FF/FC car and expect our car to have .40" (twenty times as thick) of Dyneema!

We'd be glad to redesign our car to meet Appendix J of the FIA standards if every other existing and new FF/FC car had to meet those standards as well. We are a LOT closer to meeting them already!

Nathan

[Jnovak]

Let me make this simple.

There are many cars out there that have panels in their bolted-together bell housings that meet the definition of stress-bearing panels, are therefore specifically prohibited by the GCR, but are considered legal because they have been interpreted to be "brackets." Those cars will fall apart, and certainly won't roll or drive without those panels in place. That seems a much more tortuous interpretation of the GCR to me (but I think it's fine those cars are allowed).

I will say, once again, that we are perfectly happy to abide by the decision of the Court of Appeals on the legality of our car under the 2010 GCR.

Nathan

Nathan, the "bolt together" or cast bell housings or transmission extensions used on many FC cars are POWERTRAIN COMPONENTS and they are attached between the engine & the transmission. Yes the powertrain in all race cars are mounted directly in some fashion to the frame as this must be accomplished in some manner. However to compare these powertrain components to your carbon panels is simply not relevant in any manner at all.

Thanks ... Jay Novak

[Wren]

There are many cars out there that have panels in their bolted-together bell housings that meet the definition of stress-bearing panels, are therefore specifically prohibited by the GCR, but are considered legal because they have been interpreted to be "brackets." Those cars will fall apart, and certainly won't roll or drive without those panels in place. That seems a much more tortuous interpretation of the GCR to me (but I think it's fine those cars are allowed).

Brackets are ok with less than 6" spacing for fasteners. They may not be carbon

[Ron B.]

Let me make this simple.

The panels serve a structural purpose.

The car will roll fine without them.

They do not meet the definition of "stress-bearing panel" in the GCR and are therefore not prohibited. The six-inch rule has been in place since at least 1985 and there has been no suggestion to change it until (supposedly coincidentally ) our car appeared.

As I've stated before, I'm not much of an intent guy. But as someone said to a buddy of mine, I could not find in the GCR that I can't have more than one engine in my car although the INTENT I'm sure you'll agree is otherwise.

That said, parsing B.1 Chassis (and continuing the beating of the dead horse)

[FONT=Univers][FONT=Univers]The chassis shall be of tubular steel construction with no stress‑bearing [/FONT]][FONT=Univers]panels except bulkhead and undertray; curvature of the undertray shall [/FONT][FONT=Univers]not exceed 2.54cm (1 inch). Monocoque chassis construction is prohibited.[/FONT][/FONT]


[FONT=Univers][FONT=Univers]The GCR prohibit stress bearing panels. Not only that - to be perfectly clear (in case you asked yourself, "Self, what is a stress bearaing panel?) - it specifically defines them:[/FONT][/FONT]


[FONT=Univers][FONT=Univers]Stress bearing panels are defined as: sheet metal affixed to the [/FONT][FONT=Univers]frame by welding, bonding, rivets, bolts, or screws which have centers [/FONT][FONT=Univers]closer than 15.24cm (6 inches).[/FONT][/FONT]


[FONT=Univers][FONT=Univers]Sheet metal. Affixed. 6". Hmm. Then further...[/FONT][/FONT]

[FONT=Univers][FONT=Univers]Body panels cannot be utilized as stress [/FONT][FONT=Univers]bearing panels, except as required for 1986 construction rules.[/FONT][/FONT]


[FONT=Univers][FONT=Univers]That's OK - they're not sheet metal, nor are they body panels. 2 down. BUT[/FONT]

[FONT=Univers]The use of composite materials using carbon and/or Kevlar reinforcement is prohibited.[/FONT]

[FONT=Univers]Dammit. Almost had it. But if I make these panels out of something other than sheet metal, carbon and/or Kevlar then I'm golden. Bracket, impact intrusion or not - it wouldn't matter (at least to me) as they would meet the letter of the rules. [/FONT]

[FONT=Univers]But there's that pesky intent thing......[/FONT]

[/FONT]

[nulrich]

Nathan, the "bolt together" or cast bell housings or transmission extensions used on many FC cars are POWERTRAIN COMPONENTS and they are attached between the engine & the transmission. Yes the powertrain in all race cars are mounted directly in some fashion to the frame as this must be accomplished in some manner. However to compare these powertrain components to your carbon panels is simply not relevant in any manner at all.

Thanks ... Jay Novak

Jay:

Can you point out the section of the FF/FC rules that covers these "powertrain components?"

I was not comparing our cockpit protection panels to the bolt-together bell housings per se, just pointing out that they are illegal in the same section of the GCR that certain people think cover our panels. (Ron: thanks for quoting the applicable section.)

FWIW.

Nathan

[Wren]

I was not comparing our cockpit protection panels to the bolt-together bell housings per se, just pointing out that they are illegal in the same section of the GCR that certain people think cover our panels.

wrong

[Cole Morgan]

First off, you all have too much time.

Secondly, If this issue can't be resolved in a timely manor online, I would like to propose a large FC/FF Rules Party at the Runoff's. It will be a $5 charge to attend, this will help pay for kegs, and rental EMT's. The first 30 minutes will be solely for drinking. After that, the gates outside the party will be locked and an all out brawl will ensue. Continuous drinking is encouraged as the free for all rages on.

I feel this is the most appropriate way to solve the issue.

Also, unlike on this forum, cheap shots will not be tolerated from either side.


I wish this could be solved some other way, but as a great Ranger Up shirt once said, "Sometimes Violence is the Only Answer"

[Cole Morgan]

Also, last time I encountered this much drama, my fiance was watching 90210. Yes, I am comparing you all to high school girls.

[Daryl DeArman]

Once again, I have no vested interest.
The rule was written all those years ago to NOT allow the strenghtening of the tube frame by any means.

Why allow metal panels fastened 6" on center then? It is obvious to me that they wanted to allow panels. They had to draw a line in the sand somewhere....they chose 6". Are you suggesting that a steel panel secured 6.01" on center doesn't provide any strengthening of the tube frame?

And Nathan and his investors don't? Some what narrowed minded on your part.

Sure they do. I'm certainly not narrow minded enough to think they don't. I simply stated that those of us who don't have a vested interest in the outcome can follow the logic of the interpretation without much difficulty.

this really won't be decided by us so what was the point?

Rick called it a long time ago...."sea-lawyering"....personally, I enjoy picking apart poorly written rules and debating various interpretations.

As far as the $20 ante...I wouldn't bet $.05 that the SCCA would get anything "right" no matter which side of this debate I was on. But that has more to do with my faith in the process and associated politics and less to do with whether I think I'm right or wrong.

[ric baribeault]

so cole.....you're finally dating older women?

[S Lathrop]

Sure they do. I'm certainly not narrow minded enough to think they don't. I simply stated that those of us who don't have a vested interest in the outcome can follow the logic of the interpretation without much difficulty.

What do you think about FF and FC since the 1986 rules? Have the classes covered by those rules done well?. Those rules were written by the CRB and the active manufacturers at the time.

Practically all the cars that make up FF and FC today were built by manufacturers represented at that meeting. Until now all the manufacturers of cars running in FF and FC have stuck to the letter and the "intent" of those rules.

Leading up to that meeting in 1986 there was a significant push to loosen the "tube frame rules" and allow aluminum monocoque construction. The argument was the same that the Radon proponents are making now for their car, cheaper, safer and we should modernize. I see a lot of tube frame cars that are racing today that predate the 1986 rules rewrite; I don't see very many monocoque cars that are even at the track. The fact is that monocoque construction is not as durable as a tube frame. The same is true for composite tubs. They delaminate with use and for the most part have to be replaced after a time. At least we could rebuild the aluminum tubs.

Look at how much trouble people have keeping the belly pans firmly attached to the bottom of their tube frames. Do you really think the Radon will not experience some problems keeping the safety panels in place?