Do I have to much weight already? Before painting

[cj]

My son and I have been working on our pinewood derby cars and i'm afraid we have too much weight on his and we haven't even painted yet.

With the wheels, axels and car it's weighing in at 4.8 oz. We haven't started on our wheels and axels yet but all were allowed to to is sand the wheels a little and sanding the normal sanding and polishing of axels. And we haven't painted yet.

We like to keep it at about 4.8 or 4.9 till the actual race weigh in and add a little weight at that time if we need it as it's much harder to remove weight.

Last year my son won the pack derby and 8th at district and ended up having to take a little of the additional weight we'd had to add at the pack derby as the pack and district scales were different slightly.

Any ideas on what we should do to get our weight down so that it will be around 4.8-4.9 after paint is added? How much weight will the paint add?

We'll be primering then our color coat and possibly a metal flake clear coat and maybe a totally clear coat.

We have also already used the wood filler to hide the look of the weights.

He's going with the same body style as last year. His car was the red and blue car with the white star on it.


And we've ran into issues with the blocks of wood in last years kits being a different weight from this years kit of like 3.8 in last year and much easier to cut and this year the block was like 4.4 and very dense and hard to cut and this years car has been very hard to get sanded as it looked like the car was fuzzy in the dark parts of the grain of wood so we added some wood filler and sanded back down those areas but the guy who cut the card kinda messed it up a bit. lol

Thanks a bunch!

Cindy

[derbydominator]

Cindy,

The paint primer and clear coat generally adds .1 to .2 ounces in our experience depending upon number of layers and how thick we apply the paint. For reducing weight, you can hollow out a portion of the car from the bottom and then cover the open area with packaging tape for aerodynamics but you're not going to have to reduce the weight very much to get it in line if any at all. You can complete the painting on the car and then hollow out the bottom after the fact to see how much you need to reduce. Keep your COM in mind when you are hollowing out as it will affect your balance point. With regard to the blocks, they are very inconsistent. We have seen BSA blocks in the mid 3's to over 5 ounces prior to cutting.

Congratulations on your past results and best of luck this year.

[cj]

Thanks so much for the help!

Can't really hollow out the bottom anymore as that's where the weight is.

Wonder if we could sand enough off and how long that woud take?

Here's my son's car this year:


And here's mine this year:


Also has anyone noticed the change in the wood block from last year? Is that normal for the weight to be so different?

We still had 2 kits from last year and one from christmas this year and the ones from last year he said was almost like cutting through butter.

Thanks

[derbydominator]

Cindy, You still do not need to remove much weight at all and sanding off wood from the car could definitely get rid of .1 ounces. I would imagine 30 minutes or so with some heavy grit would get you there. If you get to 4.7 or low 4.8 range with body, wheels, axles and weight prior to painting, you should be fine as long as you spray on thin paint layers.

Darryl

[cj]

Can't thank you enough!!!!