Tail_Gunner
Admiral
- Joined
- Jan 13, 2006
- Messages
- 6,237
Comments on this stinger construction
http://bateau2.com/content/view/144/28/ <br /><br /><br />Stringers: <br /><br />Measure your stringers before taking them out. Write down their depth every foot starting from the transom. You can also make a cardboard template to use to cut the new stringers from. <br /><br />Take the stringers out and grind the fiberglass down to the hull. <br />Fabricate new stringers from plywood or foam core. <br />Standard sheets of core material, plywood or foam, are usually cut from 4x8' panels. We can not cut the stringers full length in one piece. <br />Stringers are made of at least two layers with seams offset or staggered by at least 2'.<br /><br /><br />If yours is deep vee hull, you may want to offset the edges on the hull sides.<br /><br /><br />There is no need to taper the edges, a step is fine. Epoxy putty will fill that step.<br /><br />The stringers will be bedded in epoxy putty then fiberglassed to the hull with biaxial tape.<br />Large stringers or foam stringers are completely fiberglassed. <br />Plywood stringers are capped with cleats, one on each side. Cleats are typically 1 square pine stock found in the trim department of a home store.<br /><br /><br />There are two points to pay attention to when installing the stringers in the hull.<br />There should be no hard spots and the top of the stringers must be in the same plane. <br /><br />Hard spots are points where a part pushes hard on the hull. (This happens only with plywood stringers.)<br /><br /><br />This picture shows a frame with hard spot.<br /><br />Hard spots concentrate loads and are dangerous. They can lead to cracks or hull failure. A stringer should distribute loads evenly all along it's length. The ideal way to install stringers is a little bit above the hull. Builders should start with a stringer that follows the shape of the hull within a 1/4. They can use small pieces of foam to lift the stringer from the hull and fill the gap with epoxy putty while building the fillet. <br /><br />The second point to watch is the top of the stringers. They must be in the same plane or the sole will not make good contact with them. This is easy to check. Run a straight edge in diagonal over the top of the stringers. It should follow the marks of the old sole.<br /><br />Floor frames temporarily fastened to the stringers will help keep them in place during the tabbing. <br /><br />When cutting the stringers for chase tubes, try to leave at least 2 of the stringer on the bottom side. <br /><br />We have not discussed changes to the stringers but if you would like to have larger fuel tanks or improve cockpit drainage, this is the time to do it by raising the stringers. <br />Don't exaggerate, keep a good safe cockpit depth but one or two inches may make a significant difference. <br /><br />Sole: <br /><br />The cockpit sole or floor is the easiest part to replace. <br />Like the other parts, it can be made of plywood or foam. The standard 4x8 panels will require fiberglass splices for the fiberglass or butt blocks if you use plywood.<br /><br /><br />The sole is epoxy glued to cleats on the stringers in the case of plywood stringers or directly to the stringers if they are made of foam. <br />Along the hull sides and bulkheads, the sole sits on a wooden or foam cleat. There is no need to bevel that cleat, epoxy putty will fill the gaps. The upper side of the sole is taped to the sides and bulkheads with one or several layers of biaxial fiberglass tape. <br />Plywood soles are usually fiberglassed with woven cloth for protection and abrasion resistance.<br /><br /><br />Do not forget inspection plates, but it is not always necessary to include a removable fuel tank hatch. <br /><br />Tools: <br /><br />By using the correct tools, your repair will be higher quality and take less time. <br />For removing old parts, a sawzall will make short and clean work. An angle grinder with both cutting wheels and grinding disks will also be needed. For cutting out the new pieces (stringer, transom, and sole) you only need a jigsaw or small circular saw. For finish work, a high quality orbital sander is needed. An assortment of clamps are also nice, but not absolutely necessary. <br /><br />Consumables/disposables: You will use a lot a disposable gloves, mixing stick, mixing cups, wood chip brushes, roller covers (epoxy compatible). It is best to buy a lot of these at the beginning. There is nothing more frustrating than having to stop work because you are out of $.30 brushes!<br /> <br />Last Updated ( Monday, 14 November 2005 ) <br /> <br /> <br /> <br /> <br /> <br /> <br /><br /> <br /> <br /> Home | Builder galleries | Message Board | How To and Tutorials | FAQ | Plan Updates | Our web sites |
http://bateau2.com/content/view/144/28/ <br /><br /><br />Stringers: <br /><br />Measure your stringers before taking them out. Write down their depth every foot starting from the transom. You can also make a cardboard template to use to cut the new stringers from. <br /><br />Take the stringers out and grind the fiberglass down to the hull. <br />Fabricate new stringers from plywood or foam core. <br />Standard sheets of core material, plywood or foam, are usually cut from 4x8' panels. We can not cut the stringers full length in one piece. <br />Stringers are made of at least two layers with seams offset or staggered by at least 2'.<br /><br /><br />If yours is deep vee hull, you may want to offset the edges on the hull sides.<br /><br /><br />There is no need to taper the edges, a step is fine. Epoxy putty will fill that step.<br /><br />The stringers will be bedded in epoxy putty then fiberglassed to the hull with biaxial tape.<br />Large stringers or foam stringers are completely fiberglassed. <br />Plywood stringers are capped with cleats, one on each side. Cleats are typically 1 square pine stock found in the trim department of a home store.<br /><br /><br />There are two points to pay attention to when installing the stringers in the hull.<br />There should be no hard spots and the top of the stringers must be in the same plane. <br /><br />Hard spots are points where a part pushes hard on the hull. (This happens only with plywood stringers.)<br /><br /><br />This picture shows a frame with hard spot.<br /><br />Hard spots concentrate loads and are dangerous. They can lead to cracks or hull failure. A stringer should distribute loads evenly all along it's length. The ideal way to install stringers is a little bit above the hull. Builders should start with a stringer that follows the shape of the hull within a 1/4. They can use small pieces of foam to lift the stringer from the hull and fill the gap with epoxy putty while building the fillet. <br /><br />The second point to watch is the top of the stringers. They must be in the same plane or the sole will not make good contact with them. This is easy to check. Run a straight edge in diagonal over the top of the stringers. It should follow the marks of the old sole.<br /><br />Floor frames temporarily fastened to the stringers will help keep them in place during the tabbing. <br /><br />When cutting the stringers for chase tubes, try to leave at least 2 of the stringer on the bottom side. <br /><br />We have not discussed changes to the stringers but if you would like to have larger fuel tanks or improve cockpit drainage, this is the time to do it by raising the stringers. <br />Don't exaggerate, keep a good safe cockpit depth but one or two inches may make a significant difference. <br /><br />Sole: <br /><br />The cockpit sole or floor is the easiest part to replace. <br />Like the other parts, it can be made of plywood or foam. The standard 4x8 panels will require fiberglass splices for the fiberglass or butt blocks if you use plywood.<br /><br /><br />The sole is epoxy glued to cleats on the stringers in the case of plywood stringers or directly to the stringers if they are made of foam. <br />Along the hull sides and bulkheads, the sole sits on a wooden or foam cleat. There is no need to bevel that cleat, epoxy putty will fill the gaps. The upper side of the sole is taped to the sides and bulkheads with one or several layers of biaxial fiberglass tape. <br />Plywood soles are usually fiberglassed with woven cloth for protection and abrasion resistance.<br /><br /><br />Do not forget inspection plates, but it is not always necessary to include a removable fuel tank hatch. <br /><br />Tools: <br /><br />By using the correct tools, your repair will be higher quality and take less time. <br />For removing old parts, a sawzall will make short and clean work. An angle grinder with both cutting wheels and grinding disks will also be needed. For cutting out the new pieces (stringer, transom, and sole) you only need a jigsaw or small circular saw. For finish work, a high quality orbital sander is needed. An assortment of clamps are also nice, but not absolutely necessary. <br /><br />Consumables/disposables: You will use a lot a disposable gloves, mixing stick, mixing cups, wood chip brushes, roller covers (epoxy compatible). It is best to buy a lot of these at the beginning. There is nothing more frustrating than having to stop work because you are out of $.30 brushes!<br /> <br />Last Updated ( Monday, 14 November 2005 ) <br /> <br /> <br /> <br /> <br /> <br /> <br /><br /> <br /> <br /> Home | Builder galleries | Message Board | How To and Tutorials | FAQ | Plan Updates | Our web sites |
Gotta see those stringers up and straight securly bonded into place.<br /><br />Just one question if i may, what type of fiberglass cloth should be used, layering (thin cloth) or thick mat type of material.<br /><br />As to the epoxy i am assuming it is there to distrbute schock evenly. Assuming that the stringer cannot follow the contour of the hull that precisley,by adding putty in a soft form with will accomdate any imperfection's aka "hard spots". Dunno if i got that right or not.