Thermodynamics B/C Build

[scandium21]

Hey guys, I am new to this event and forum and was wondering if my building ideas are feasible:
I was thinking of buying a Styrofoam box and filling it with spray polyurethane foam from a can (https://www.amazon.com/gp/product/B000U ... 0DER&psc=1) .
The box is a little big (Div. C), so I will have to sand it, but I think it will require minimal building and cutting. My idea was to place the beaker in the box and spray polyurethane foam around it to get it really snug. Is this design feasible or effective, and should I consider adding something else such as Mylar sheeting? Thank you and sorry if I broke any forum rules.

[Creationist127]

Hey guys, I am new to this event and forum and was wondering if my building ideas are feasible:
I was thinking of buying a Styrofoam box (http://www.amazon.com/gp/product/B007PB ... OKA6&psc=1) and filling it with spray polyurethane foam from a can (https://www.amazon.com/gp/product/B000U ... 0DER&psc=1) .
The box is a little big (Div. C), so I will have to sand it, but I think it will require minimal building and cutting. My idea was to place the beaker in the box and spray polyurethane foam around it to get it really snug. Is this design feasible or effective, and should I consider adding something else such as Mylar sheeting? Thank you and sorry if I broke any forum rules.

That sounds like an okay idea. One piece of advice I would give: when you spray the spray foam around the beaker, there is a good chance that the beaker will get stuck inside. You might want to try covering the beaker with plastic wrap (a.k.a. cling wrap, Saran wrap, etc.) when you spray the spray foam, making it easier to get the beaker out.

[CookiePie1]

Hey guys, I am new to this event and forum and was wondering if my building ideas are feasible:
I was thinking of buying a Styrofoam box (http://www.amazon.com/gp/product/B007PB ... OKA6&psc=1) and filling it with spray polyurethane foam from a can (https://www.amazon.com/gp/product/B000U ... 0DER&psc=1) .
The box is a little big (Div. C), so I will have to sand it, but I think it will require minimal building and cutting. My idea was to place the beaker in the box and spray polyurethane foam around it to get it really snug. Is this design feasible or effective, and should I consider adding something else such as Mylar sheeting? Thank you and sorry if I broke any forum rules.

That sounds like an okay idea. One piece of advice I would give: when you spray the spray foam around the beaker, there is a good chance that the beaker will get stuck inside. You might want to try covering the beaker with plastic wrap (a.k.a. cling wrap, Saran wrap, etc.) when you spray the spray foam, making it easier to get the beaker out.

How you build your device is really up to you, and it's more of a trial-and-error thing in nature. However, I would definitely advise NOT using plastic wrap around your beaker when spraying, because that will definitely get stuck. instead, use a paper towel or something, or you could even spray first and cut out space later. However, if you do choose to spray with your beaker inside, it will most likely be very difficult to insert and remove your beaker, so be careful with that.

[RockRoll92]

When testing our thermo device should the starting water temperature within the guidelines (60C- 75C irrc) be before pouring or afterwards. In other words should you pour the water into your device and wait until it becomes the goal temperature then wait an amount of time or pour goal temperature water into your device and start waiting then?

[jaggie34]

It should be 60-75 degrees Celsius before pouring

[CookiePie1]

It should be 60-75 degrees Celsius before pouring

This is very important. If you pour it into your device and wait for it to cool, your device is also rising in temperature which will affect your predictions and performance. The rules specify a source bath, so at competitions, the water will be poured into your device after it reaches temperature. As a general rule of thumb, it's always good to mirror competitions so you get the most accurate results.

[geniusjohn5]

Anybody have any good videos/links (free) that show steps on how to build the device?

[C8H10N4O2!]

Hey guys, I am new to this event and forum and was wondering if my building ideas are feasible:
I was thinking of buying a Styrofoam box (http://www.amazon.com/gp/product/B007PB ... OKA6&psc=1) and filling it with spray polyurethane foam from a can (https://www.amazon.com/gp/product/B000U ... 0DER&psc=1) .
The box is a little big (Div. C), so I will have to sand it, but I think it will require minimal building and cutting. My idea was to place the beaker in the box and spray polyurethane foam around it to get it really snug. Is this design feasible or effective, and should I consider adding something else such as Mylar sheeting? Thank you and sorry if I broke any forum rules.

That sounds like an okay idea. One piece of advice I would give: when you spray the spray foam around the beaker, there is a good chance that the beaker will get stuck inside. You might want to try covering the beaker with plastic wrap (a.k.a. cling wrap, Saran wrap, etc.) when you spray the spray foam, making it easier to get the beaker out.

How you build your device is really up to you, and it's more of a trial-and-error thing in nature. However, I would definitely advise NOT using plastic wrap around your beaker when spraying, because that will definitely get stuck. instead, use a paper towel or something, or you could even spray first and cut out space later. However, if you do choose to spray with your beaker inside, it will most likely be very difficult to insert and remove your beaker, so be careful with that.

IDK if youve already tried this, but I did a while ago, and it was awful! I made a box out of thin plywood, used corner brackets (or whatever they are called) and glue to hold the box in place, placed stilts for the beaker on the bottom and on the top of the lid (so that I would get the spot where I wanted it), wrapped the beaker in aluminum foil, drill a hole through the lid of the plywood box, clamped it down, and sprayed the stuff in there.

My main problem with this was I could NEVER get consistent results, and the more I tested it, the worse the results got too!!!! Just putting this out there in case anyone is trying it, I'm not an insanely good builder, but I promise I'm somewhat decent, and this did not work for me. I would recommend sticking with some type of foam. You may not get the k-value you want, but quite honestly, with the differing start temperatures of the water between competitors (as the ES's hand out water differently), its basically luck for that anyway. Focus on the prediction, its worth more points and less dependent on event supervisors messing up.

[lianasv]

hmm, yesterday at the COBRA invitational in MI, they left the thermometer in the beaker for the whole 25 min when measuring the temperature. Is that allowed since the heat is escaping my device by the thermometer??

[John Richardsim]

hmm, yesterday at the COBRA invitational in MI, they left the thermometer in the beaker for the whole 25 min when measuring the temperature. Is that allowed since the heat is escaping my device by the thermometer??

There's a statement in the rules in section 4.f. saying that they can do this, but it they must announce that they are doing so before impound.