Secure Gravel Bags Secure Gravel Bags are made from the same strong fray resistant material as Secure Covers. They hold the Secure Covers in place and make a more complete seal than tyres. Secure Gravel Bags are available in packs of 20 (supplied with heavy duty cable ties). Each bag weighs between 15-20 kg when filled with pea gravel. The integral handle makes moving the bags a simple task. Filling Secure Gravel Bags Secure Gravel bags should be filled with 2cm pea gravel or stone to 25-30cm from the top. Try using a traffic cone with the end removed as a funnel to make the job easier. Zip tie the bags 10-15cm from the top. Do not overfill the gravel bags. The bags need to remain flexible to seal the silage clamp and to prevent bursting if the bag is dropped. Using Secure Gravel Bags Unlike tyres Secure Gravel Bags are flexible and they focus weight on the shoulders at the junction of the sidewall and silage sheet. This stops air and water getting into the silage and prevents spoilage. Secure Gravel Bags should be placed ‘nose to tail’ around the edge of each Secure Covers, including where the Secure covers overlap. Keep the Secure Cover in contact with the silage sheet during feed out by placing a line of Secure Gravel Bags along the leading edge. Secure Gravel Bags can be easily stored on a pallet when not in use. Do not drag Secure Gravel Bags across rough surfaces.