I am building an older model (Bingo by Dumas) and I need some advice on how to get the right amount of ballast for the boat.

If you have the designed displacement, see my posting in RCGroups.

Otherwise the person who is most likely to know is Earl Boebert, who will probably be looking at this thread soon. Just in case, send him a message.


I’m not familiar with that particular design; did you want to know how to find out the amount of ballast to use, or where to locate ballast material?



I was looking for the amount of Ballast.

The easiest way is to float the hull. You’ll need some lead or steel shot; if you’re in the US, lead shot is usually available on eBay. It’s handy stuff to have around for trim ballast or to make special weights for one shop purpose or another.

Get some baggies and fill one with shot equal to the weight of your radio gear and batteries. If you don’t have an accurate scale, a simple home made balance will work for this task. Make up a set of 2 lb baggies. Again, if you don’t have an accurate scale use the one in the lobby of your local post office (you’ll get some weird looks, but that’s the price of a hobby :-)). Load the radio weight in the hull and add and move baggies until she floats on her lines. I find most M hulls are happier if they float about 1/8" above their lines at the stern and 1/4" above at the bow. You’ll probably have to remove some shot from the last baggie to get it right. Count the baggies, weigh the last one, and that’s the size bulb you’ll need to buy.



Thanks Earl. Cant wait to go to the post office now. LOL