stringer and transom info - replace transoms with something other than plywood?

Discussion in 'Boat Design' started by jimmy wise, Nov 4, 2013.

  1. jimmy wise
    Joined: Nov 2013
    Posts: 25
    Likes: 1, Points: 0, Legacy Rep: 46
    Location: reno nv

    jimmy wise Junior Member

    just wanted to say hi. great information here. i was wondering if someone could help me with some stringer and transom info. id like to be able to replace transoms with something other than ply wood. ive heard you can core stringers with foam and glass in. i dont think the foam would work for the transom. also is there a type of pipe glass sticks to for drains through stringers? thanks again jimmy
     
  2. Easy Rider
    Joined: Oct 2009
    Posts: 920
    Likes: 46, Points: 0, Legacy Rep: 732
    Location: NW Washington State USA

    Easy Rider Senior Member

    There's always cut lumber.

    If we knew why you didn't want plywood ......
     
  3. jimmy wise
    Joined: Nov 2013
    Posts: 25
    Likes: 1, Points: 0, Legacy Rep: 46
    Location: reno nv

    jimmy wise Junior Member

    trying to come up with a marketable repair eliminating rot. my boat is all plywood, stringers too. just was wondering if there was an option thats all. it was an assload of work fixing a boat that was built shitty..... stringers were dimensional but only glassed half way up. i got alot of help from people on iboats. some are here to. jimmy
     
  4. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 471, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    There are only a few ways to repair a transom. The cheapest way is with a plywood core, well tabbed to the hull shell. You can also use more inert materials, though the costs can just up potentially, particularly with high tech materials.

    Rot in wooden boats is a owner issue, not a material issue. You can keep up with the maintenance or pay the price when you don't. Of course, building techniques also has a lot to do with it, which you've found in your stringers. Built properly and reasonably cared for a wooden core lasts a very long time. On production boats, they still use plywood cores, again because it's cheap, but even with absolutely zero care, this type of core can last 20 years, so you have to ask yourself, how much durability do you expect. I have a 1957 runabout (all wood) that has it's original transom and stringers. It hasn't received great care over the years, but has received enough to prevent it from rotting out. So, it is possible to have a long lived wooden transom.
     
  5. jimmy wise
    Joined: Nov 2013
    Posts: 25
    Likes: 1, Points: 0, Legacy Rep: 46
    Location: reno nv

    jimmy wise Junior Member

    I guess a little back ground on me.. i have done auto body, paint and uhpolstery for 30 years. i closed my body shop because my market is saturated with shops and its not profitable anyway. i am basically an uhpolsterer now full time. for the record i have done fibreglass repair for years, of course it was mostly wrong. after some professional guidance from ondvar and others from iboats forum i feel im ok enough to do repair work. but by no means am i minimizing the amount of knowledge i need to learn. i have just scratched the surface of this. as for painting i am fully trained on all the little quirks and things. so i understand there is only 2 million things i would love to know right now. im rebuilding my old 1980 marlin bow rider for learning and understanding of boat problems. my transom is done with two layers of 3/4 ply glued with titebond three and stainless screws. i coated the ply with resin and the transom also, then i wet a layer of 1708 and clamped and screwed it in. i now know csm would have been fine. the inside is a layer of 3oz mat, a layer of 1708 rolled in, a layer of 18oz roving and tabbed to hull every 8 inches with 6 inch by 1 foot 18 oz roving. i was advised that the 1708 was not the right choice. i doubt it will break lol. the thickness is ok for the out drive. the original transom was one full layer and a second layer just in the middle.
    the stringers are also ply laminated with staggered joints same screws and glue. they are bedded in pl 400 or what ever the adhesive is. but its the one recommended. they are filleted with pb made with resin and cab. they are covered in one layer of 3oz mat and a layer of 18 oz roving. its a good thing its my boat because i got to learn how to radius ply in the hull to make roving wrap over. if the roving wasnt super cheap i wouldnt have used it . i also tabbed to the hull with 6 buy 1 foot 18 oz roving tape.
    i need to drill the drain holes in the stringers, is there a pipe resin will stick and seal with or do i just make my own pipe lol?

    Of course after i did all of this i ended up with a venus chopper set up for very cheap. i need packings because they left resin in the pump. its internal mix with acetone wash. im in it an old mig welder from my shop. anyplace sell a/m seals or just venus?

    i still have glass work to do and i love the whole wet out gun concept ;)

    I am going to see about making some seating for boat and hotrod using glass shells but i was thinking about advertizing for stringers and transom work. by the time most boats need upholstery the floors are shot....you know the drill....so i was looking for a no rot solution to offer. but now i understand wood works. i came to this forum because of the experience and the knowledge. thanks for your help.

    i feel like a newbie over here and hope i dont bother you guys with stupid questions. im already getting boat professionals telling me that you just section in the bad wood lol. just patch the lower rot in the transom.
    i feel also that your knowledge is worth something so if i can trade any upholstery knowledge i would love to.

    Gel coat!!! whole other section. boat has pimples on bottom . so i could use a peeler uhg. after i remove it and fix glass work can i duratec the bottom. is it like featherfill? ill ask about the gelcoat later i better get to work... thanks again jimmy
     
  6. boatbuilder41
    Joined: Feb 2013
    Posts: 159
    Likes: 3, Points: 18, Legacy Rep: 56
    Location: panama city florida

    boatbuilder41 Senior Member

    Drilling stringers for drains is probably the most common problem that leads to premature failure of stringers., I would say that not sealing the stringers properly is really the biggest problem. Just because the stringers appear to be encapsulated and waterproof doesn't mean they are waterproof.polyester resin is very water resistant..... but not waterproof. Most production built boats do not have gelcoat or any other type of sealer on the stringers or anywhere below the decks. I have had g ood luck with solid fiberglass stringers. .normally that would be expensive and unnecessary. But I always find myself looking for a better way to do things. I don't know that it is better. But its less rot. I do need to clarify that its not actually solid glass. I found that I had to glass a strip of wood to the top of the stringers to fasten the deck. I got it down to a minimum of labor involved. My aching body can't take bending over in the boat to glass. Up and over the stringers and back down the other side lapping on to the hull again. Now I make a template. Copy to stringer, fit stringer, remove from boat, glass wood on top. Now when I put it in the boat I only have very little to glass in the boat.just lap stringer to boat with only one radius on eash side. This makes instalation about half the time. Therefore the savings in labor can be added back to the higher cost of solid glass stringers. Now everybody is happy. That means a better boat for the same amount of money... and my back don't hurt....... and drill all the holes that you want. It works for me
     
  7. boatbuilder41
    Joined: Feb 2013
    Posts: 159
    Likes: 3, Points: 18, Legacy Rep: 56
    Location: panama city florida

    boatbuilder41 Senior Member

    I just wanted to add that when I have to put wood decks in a boat.... I drill multiple two inch holes all throughout the stringers. Just randomly from top of stringers to the bottom. I find in most (not all ) cases, it is better to properly ventilate the bilge. That becomes near impossible without drilling multiple holes for circulation
     
  8. jimmy wise
    Joined: Nov 2013
    Posts: 25
    Likes: 1, Points: 0, Legacy Rep: 46
    Location: reno nv

    jimmy wise Junior Member

    im going to seal the stringers with gelcoat and the bildge. transom also. the reason i was asking about a pipe, was so i can glass the drains in solid. im going to make the deck drain to the rear but i need to get through the stringers and glass them. evey hole in the boats transom will be drilled and them drills larger on the inside and filled with pb. then redrilled so the transom dosnt crush and rot
     
  9. boatbuilder41
    Joined: Feb 2013
    Posts: 159
    Likes: 3, Points: 18, Legacy Rep: 56
    Location: panama city florida

    boatbuilder41 Senior Member

    You can get fiberglass tubing in all different sizes. Fiberglass exhaust tubing and fiberglass shaft log tubing which is normally a lot thicker wall.
     
  10. boatbuilder41
    Joined: Feb 2013
    Posts: 159
    Likes: 3, Points: 18, Legacy Rep: 56
    Location: panama city florida

    boatbuilder41 Senior Member

    Just wanted to add..... I been building boats for a long time. My father and grandfather built boats. I grew up with boatbuilding. I can't remember a time in my life that I couldn't look over either shoulder and see a boat. But I don't know it all.......nobody does. Im still a junior member here myself. I found this site to be very informational with a lot of very well educated members. .....just remember that "LIFES MOST VALUABLE LESSONS LEARNED, ARE LEARNED FROM FAILURE, NOT SUCCESS".....but I found it to be a hell of a lot cheaper to just ask somebody
     
  11. jimmy wise
    Joined: Nov 2013
    Posts: 25
    Likes: 1, Points: 0, Legacy Rep: 46
    Location: reno nv

    jimmy wise Junior Member

    where do i get fibreglass tube? i can make it but i would like to get it made if possible
     
  12. boatbuilder41
    Joined: Feb 2013
    Posts: 159
    Likes: 3, Points: 18, Legacy Rep: 56
    Location: panama city florida

    boatbuilder41 Senior Member

    Advanced plastics. Or most big fiberglass supply places will have it
     
  13. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 471, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Really, 'glass tubes? Wax up a length of 1.5" PVC pipe then wrap, whatever fabric you want around it and wet it out. Use a chop saw to cut to length as desired. Don't make the tubes any bigger then the bulkhead or partition is thick, so it can't trap moisture where it "peeks" through these areas.
     
  14. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 114, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    A common mistake when installing thru frame drain tubes is boring the hole too small. If you bore a one inch hole then fit a one inch tube , the joint will be epoxy starved and will leak.

    Oversize the hole, bevel the edged, push the tube into the epoxy primed oversized hole, use a small shim under the bottom to center the tube in the hole, pump thickened epoxy into the gap, then finish off with a fillet.


    Best if you let the tube extent too much on each side of the frame then trim and clean up after cure.
    Dont disturb the tube until the epoxy has cured.
     

  15. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 471, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I see no reason for the tubes, frankly. Precut the weeps, well saturate them with resin, use fabric if you must, but that's about all you need - a well sealed weep hole.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.