Silica gel packs do help but wont completely prevent rust. I keep probabaly 10-20 in each box and still will get rust at times. Taking boxes out after a rain and putting a fan on them is a must also. Open up you boat compartments as well w a fan on them. You can easily get silica packs for free too. Just ask at your pharmacy. My wife works at a pharmacy and I get them by the box. They always have them sitting around. Plus the pharmacy typically has the silica in the hard plastic cylinders. Theyre alot easier to deal with.