Use of "Great Stuff" (liquid foam)

[Craigs Cruzer]

Has anyone tried using "Great Stuff" to fill the cavities on a ladder car to add rigidity rather than using the 1/64" board down the full length of the car? This is for a scout race, so we want to beef it up a little but minimize the weight increase. We're wondering what the benefits/drawbacks may be. My guess is that the 1/64" is already pretty light and the difference may be negligible. I could see there being added rigidity if both are used, but only having spray foam may be worse than just the board.

 

[Loud2ns]

Has anyone tried using "Great Stuff" to fill the cavities on a ladder car to add rigidity rather than using the 1/64" board down the full length of the car? This is for a scout race, so we want to beef it up a little but minimize the weight increase. We're wondering what the benefits/drawbacks may be. My guess is that the 1/64" is already pretty light and the difference may be negligible. I could see there being added rigidity if both are used, but only having spray foam may be worse than just the board.

Use the 1/64.

 

[DerbyDoctor]

I made a car once with lightly epoxied in xps foam board to fill the cavities. On a thin car, the width of foam isn't enough for it to provide the rigidity you are looking for and the added weight, although very light, did slow it down some.