Prepping for district

[having_wandered]

Ok so our Scout is headed to district in just over 1 month. I see notes a about blowing out the old graphite and replacing with new due to moisture absorption. My question is in regards to timing. When should I blow out the old, and when to add the new?

[sporty]

Hmm,

can you direct me to the post that recommends blowing out the old ? and due to moisture ?


I just ask, because I have not seen this recently. Id like to read it.

if your car was in a sealed bag, and kept in the house. you should be fine. for years our packs impound the cars in Jan, the winners that go to council, that race is in April. and we were not allowed to relube, ect, the cars stayed sealed until race day infront of the inspector. we got to add lube before the cars were sealed but that was it.

I never had a issue and we went on to win council many times, comprised of 5 districts.


Still tho, if given the chance, Id likely re polish the axles and clean the wheels, re prep the wheel bores and relube.

I just never ran into a moisture issue in 12 years. But maybe you had your cars in the garage or theres some rapid moisture change that is worse then illinois.

But, Id likely do all my re working and prepping, ect. within 24 hours of the race.

Sporty

[having_wandered]

Well we raced in a building where there was a fair amount of dust in the air. Also the car went from warm house, to very cold car etc. So I figured if anything there might have been some condensation and at the very least dust particles that need to come out. I like your time for retouching, think I'll clean them now, have my Scout give them a light dusting tonight and then do a full lube prep the day before.

[j.m.]

It takes about 1 month for moisture in the air to compromise the graphite lube. I know that the lubes will absorb moisture, and turn to a sulfur oxide, thus corroding the axles a little. I know that when I leave the car sit for that month between pack race and districts, the axles will get a darker color to them. We usually pull the wheels and repolish everything the week before districts, then lube up and assemble the night before the race.

[Shawn Stebleton]

Has anyone tried a desiccant? You know, those packets included in various store items such as new shoe boxes that say "Do Not Eat" on them? They absorb moisture from the air--that's their job. Would it make sense to put one in a zipper bag with a PWD car? It would reduce or eliminate condensation, I would think.

We only have 1 (or this year, 2) weeks between pack and district, so we never worried about it. Also, our house is dry in the winter--humidity below 50%. We haven't thought about using one during transport, though.

[Speedster]

My concern would be that more harm than good might occur by taking the car apart. Does the car turn the exact same time, or better times, after the car has been taken apart? If the car has been carefully taken care of between Pack and District, which I'm sure it has been, is there really that much damage been done to the axles where the wheels will ride? I would run the car against the timer before the Pack race. If you win 1st place in your Pack I would then run the car against the timer a few days before the District race. If you still have the same speed I would leave it alone. FWIW, I have a 3 year old District winner that runs the same speed today as it did 3 years ago.
Best of Luck.

[resophonic racing]

Has anyone tried a desiccant? You know, those packets included in various store items such as new shoe boxes that say "Do Not Eat" on them? They absorb moisture from the air--that's their job. Would it make sense to put one in a zipper bag with a PWD car? It would reduce or eliminate condensation, I would think.

We only have 1 (or this year, 2) weeks between pack and district, so we never worried about it. Also, our house is dry in the winter--humidity below 50%. We haven't thought about using one during transport, though.

The best thing you can do for a car between a pack and district race is clean and re-prep the wheels. Debris and graphite from a scout race are major time killers once they get on your wheels. Assuming you can duplicate your alignment.....a good cleaning and re-prep are all you need. I think we focus way too much attention on the lore of pinewood derby instead of doing the simple things that can help a car go faster.

[j.m.]

The other reason we pull ours apart, is we run on an alluminum track for pack, and the DFW gets chewed up from riding the sharp rail. That wheel gets the inside edge resurfaced for a smoother new run. Also, our cars seem to run their best with fresh cleaning and lube, and since districts is only a 3 run race with times added, our best shot is with a fresh assembly. Also, our pack race usually means that the top 3 cars will run about 13-16 runs till all said and done. I just can't let it go without re-prepping.

[FatSebastian]

the DFW gets ... the inside edge resurfaced for a smoother new run.

Can you elaborate as to your resurfacing procedure?

[chromegsx]

Has anyone tried a desiccant? You know, those packets included in various store items such as new shoe boxes that say "Do Not Eat" on them? They absorb moisture from the air--that's their job. Would it make sense to put one in a zipper bag with a PWD car? It would reduce or eliminate condensation, I would think.

We only have 1 (or this year, 2) weeks between pack and district, so we never worried about it. Also, our house is dry in the winter--humidity below 50%. We haven't thought about using one during transport, though.

I did this for the two days between final assembly/alignment and race night while the car sat inside a small semi sealed container. Don't know if it did anything to help or hurt, but when I did it... I went under the assumption it couldn't hurt. Later I ran across a post somewhere there graphite needed some moisture to work best, but could never verify that claim, although, admittedly I didn't try hard since the race was over.

[j.m.]

the DFW gets ... the inside edge resurfaced for a smoother new run.

Can you elaborate as to your resurfacing procedure?

If it is really chewed up, I spin it on a lathe with a special fixture I made to hold the wheel. If it isn't too bad, we just cut a hole in 600 grit sand paper for the inner hub to fit through, on the drill press table with slots. Then we can sand the edge down till the chew marks are out. Then it goes into the drill press chuck for re-rounding the edge and polishing. I should have taken a pic of this years wheel, it was pretty bad. So this years wheel whent onto the lathe to speed up the removal of plastic. Otherwise, the whole process could be done with sand paper, but takes longer.

[Stan Pope]

Can you elaborate as to your resurfacing procedure?

If it is really chewed up, I spin it on a lathe with a special fixture I made to hold the wheel. If it isn't too bad, we just cut a hole in 600 grit sand paper for the inner hub to fit through, on the drill press table with slots. Then we can sand the edge down till the chew marks are out. Then it goes into the drill press chuck for re-rounding the edge and polishing. I should have taken a pic of this years wheel, it was pretty bad. So this years wheel whent onto the lathe to speed up the removal of plastic. Otherwise, the whole process could be done with sand paper, but takes longer.

Neat!

Tell us about the "special fixture".

How many times can you repeat this process before the wheel is too narrow to pass inspection?

[j.m.]

I guess it depends on the inspector of the day. I wouldn't go any farther then the radius that comes on the wheel. Probably would only need to do it once anyway, as the wheel is good from new for the pack race, and then only need to prep for districts. At least for out area, there is no further races after districts. I will post a pic this week of the arbor that use to true up the wheels. I still have it at work, as that is the only place I have access to a lathe to use it.