Information/Advice on Deck Removal

Discussion in 'Fiberglass and Composite Boat Building' started by JimS, Oct 19, 2011.

  1. JimS
    Joined: Oct 2011
    Posts: 21
    Likes: 1, Points: 0, Legacy Rep: 16
    Location: Niceville, Fl

    JimS Junior Member

    Got back on the boat today after being gone for a bit, got most of the decking and foam out of the port side. Attached some pictures, looks like the form may provide some structure and support, like to hear your opnion. The wood was really rotten, but the foam was bone dry, guess they used some good stuff when they put it together. Some of the craftmanship is sad, lots of adding and patching wood with no resin to fill voids they missed. Well got the chance to do it right. I decided to use the West System epoxy after reading up on blush as suggested. Costs more but I think I won't have to worry about it when I'm done.
     

    Attached Files:

  2. JimS
    Joined: Oct 2011
    Posts: 21
    Likes: 1, Points: 0, Legacy Rep: 16
    Location: Niceville, Fl

    JimS Junior Member

    Making some Progress

    Able to get back in the boat last week and will hit it today if the weather will cooperate. Just about got the transom removed and it was built from two pieces of 3/4 ply. Want to be sure I build it properly so here is my plan, appreciate any advice/comments on it. Was going to install in two pieces, first piece after coating with three coats of epoxy will get attached to the prepared transon with epoxy thickened with silica and 1/4 fibers. Clamped up to set. Next piece after three coats of epoxy will get attached to first layer with epoxy only and clamped up. Will fillet all the way around with thicknened epoxy and will tab in with 1708 cloth (not mat), probaly four layers. Finish off with one or two layers of the same 1708. Reasonable plan?


    I have spent hours reading up on stringers, lots of different ideas out there. Mine are also 3/4 ply and had no bedding. Really need some advice on bedding them in, should I set them in a bed of thicknened epoxy? Last question is construction, my stinger/bulkheads used a cross half joints where they intersected. Is this a good practice, see lots of troops just use a butt joint. Want to do this right, but also make fabrication as easy and sound as possible. Thanks and look for the replies

    Jim

    IMG_4957.JPG

    IMG_4961.JPG
     

    Attached Files:

  3. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 491, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    1708 is a "combi-mat" type of product. It has both mat and cloth stitched together. You can use it, but it drinks up a lot of resin during wetout, which isn't especially strong, not to mention wasteful. Use a straight biax cloth (> http://boatbuildercentral.com/proddetail.php?prod=E_bias_12oz_50 <)

    I'd place both pieces of plywood core together at the same time as I bond it to the boat. Orienting the grain is a good idea. Arrange the two pieces so they cant at 22.5 degrees from horizontal (opposing each other of course). A slightly thickened epoxy mix will fill voids and any gaps that might turn up, when bonding the two halves.

    I'd install the two pieces, fillet and tab all in one shot if possible. It's a long day of goo work, but it's the best way for strength.

    You can bed your stringers in epoxy fillets, foam, a big fat bead of polyurethane or whatever. I like them bonded with fillets (on your type of hull shell), as I'm in the goo mode anyway and the laminate is fairly thick.

    I don't like notching stringers, it weakens them longitudinally. Generous fillets to the bulkhead will do just as well and not weaken the stringers.

    Lots of tabbing, as this is a common place where the manufactures cut corners, making a weak structure (as you've seen). Healthy over laps and extended well out onto the cleaned and toothed up hull shell.

    Lastly, West System is good stuff, but you can get epoxy with the same physical properties for over half the price of West. Look at the link above and check their Marinepoxy. The only West I use are their specialty epoxies.
     
  4. tunnels

    tunnels Previous Member

    1708 is a "combi-mat" type of product. It has both mat and cloth stitched together. You can use it, but it drinks up a lot of resin during wetout, which isn't especially strong, not to mention wasteful

    Ok lets have a look at this statment
    It drinks up a lot of resin !!
    why does it drink lots of resin ?? which isn't especially strong, not to mention wasteful!!:eek:
    What ever glass you are using will only take what is needed to be use for the weight of glass no matter what combination of differant glass you re using !!
    Use peel ply and get the glass compressed and if there is surplus ressin it will get ripped off when you take the peel ply off !
    1708 is a "combi 45/45 glass + a chopped strand matt"so if you think its going to drink lots of resin why use it in the first place ?? Its a good glass to use anyway as it has a bedding layer of chopped strand matt to put against the rought surface you probably have !!
    If you are using plain Double bias its a slightly better choice !,No chopped strand matt just glass ,45/45 and 100% of the strands will work in combination to each other !! glass oriantation its called
     
  5. JimS
    Joined: Oct 2011
    Posts: 21
    Likes: 1, Points: 0, Legacy Rep: 16
    Location: Niceville, Fl

    JimS Junior Member

    Thanks for the response

    Great advice, many thanks. I will get 17 oz biaxial cloth, no mat for the project. I will be getting the epoxy recommended, only focused on the West System because I could get it locally, but even with shipping looks like I will be ahead. I will not notch the stringers. (Thats a relief!)

    Did have two additional questions, not familiar with peel ply, can you give me more info on that. Also, when I put three coats of epoxy on the stringers/transom lummer can I due them one after the other or do I need to wait for each coat to dry? Again, thanks for the quick response

    Jim
     
  6. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 491, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    1708 is a 17 ounce biax stitched to an 8 ounce mat. The mat takes up a lot of room and yes it can be mashed down (offering little strength), but it's resin/fiber ratio will always be high, compared to cloth or directional fabrics. This is why it drinks resin. Even if you use peel ply, you've wasted resin, which is costly.

    Peel ply is a "release fabric", applied over a laminate, which seals it from the environment and permits excess resin to push through (the wasting resin process in action), as you work out bubbles and move resin around under it. It can control blush issues and offer a good surface for the next coat of whatever. West 105/205 206 will blush, so consider a peel ply, with this consideration. If you're repair environment will produce lots of dust, dirt, bugs etc. in your dried goo, then skip the peel ply and save some money. This is because you have to clean and sand the surface before any subsequent layers or coatings go down, negating the need for peel ply. You can work cleaner with peel ply, but if you're going to be grinding and sanding on something after wards, then skip it.

    You can apply another coat of epoxy as soon as the previous coat has "gelled", which is a tacky state, but no longer liquid. Most wait until it's lost some of it's tackiness. You don't have to wait until it's dry and it's preferred that you don't.
     
  7. JimS
    Joined: Oct 2011
    Posts: 21
    Likes: 1, Points: 0, Legacy Rep: 16
    Location: Niceville, Fl

    JimS Junior Member

    How to Deal with the Transom

    Well , still chipping away at this restoration project when time permits. Posted some pictures and would like some advice on the transom prep. As you can see there are some voids and gouges, should I skim it over with thickened eboxy and resurface prior to bonding wood to it? A layer of cloth? Also, any advice on removing the coating from the bildge( white/gray color), not sure if its gelcoat or epoxy but it just laughs at my grinder with 36 grit paper. Any tips or suggestions. Thanks in advance, we're slowly getting there.

    Jim
     

    Attached Files:

  8. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 491, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The roughness of the transom isn't a problem with thickened epoxy. A notched trowel (1/8") will solve this problem, when you bond the plywood in.

    The white stuff in the bilge is gel coat, probably pretty thick too. Stop using sissy paper on your grinder and drop down to 16 or 24 grit and piss it off, instead of it pissing you off.
     
  9. midnitmike
    Joined: Apr 2012
    Posts: 257
    Likes: 20, Points: 0, Legacy Rep: 167
    Location: Haines and Juneau

    midnitmike Senior Member

    I did a job similar to this one two summers ago, minus the cap removal experience (thank goodness). Being a strictly glassman myself I stayed away from the epoxies solutions that so many here seem to prefer. When it came to the transom area the customer wanted to do away with the outdrive cut out so that was glassed in first and faired inside and out. We cut a pattern for the new transom piece out of cardboard, and transfered that to our two 3/4" pressure treated plywood pieces. Instead of thickened epoxy I mixed up a 5 gal bucket of Cabosil, and just as Par suggested troweled that on over the surface. Getting a good void free bond can be problematic no matter what medium you use. Clamps may not do the trick, and in our case wouldn't have worked at all since we had no hull cut-out. Our solution was to apply the filler, set one sheet in place and brace it with stiff legs and 2x6 supports running across the width of the transom. Granted it wasn't perfect, but we managed to get a pretty decent bond as evidenced by the cabosil oozing out from under the edges.

    Since the plywood edges had been prepped prior to installation I simply used the excess cabosil to fair them in prior to glassing. A layer of matte, biaxle, matte were applied once the cabosil had kicked, and allowed to harden over night. Then the second plywood piece was positioned over the first, and secured as before. Again this was faired in around the edges using cabosil and allowed to kick. The final lay-up was two alternating layers of 1 1/2 oz matte and 1708 biaxle.

    The new transom was considerablely stronger then the original with fewer places for water penetration and hopefully a better laminate then stacking two pieces of plywood and then glassing over both.

    I know this might seem like overkill to some so I should mention that an aluminum transom was later mounted (through bolted) and a 225 hp strapped to it. The boat does 47 knots and the customer says there's no flex in the transom whatsoever.

    MM
     
  10. JimS
    Joined: Oct 2011
    Posts: 21
    Likes: 1, Points: 0, Legacy Rep: 16
    Location: Niceville, Fl

    JimS Junior Member

    Thanks fellas, I'm off to the store to get some manly paper, and attack that coating. I already got the epoxy and 17oz biaxial with no mat. So I am going to coat the transom pieces with three coats of epoxy, cut them on a 25 degree off set to the grain, attach to the transon with epoxy thickened with cabosil, second part of transom attached to first with thickened epoxy and clamp and filet the whole thing. Going to tab in the transom with the 17oz biaxial, probaly four layers out to eight inches. Top the whole transom of with two layers. Let me know if that sounds like a sound plan, be good top put some wood back in this heap.

    Jim
     
  11. tunnels

    tunnels Previous Member

    The motor mounts ! They also need to be up dated to seeing you are getting carried away with everything else . take the from the new transom as far forward as you can in one piece and glass them well . they have to support tha whole weight of the motor down onto the hull and the longer the area the lpad is distributed over the better specially when you come off a wave and pound into the next one . Its a wonder there are not stress marks in the gell coat along the hull bottom where the stringer was !!:eek::D:p
     
  12. JimS
    Joined: Oct 2011
    Posts: 21
    Likes: 1, Points: 0, Legacy Rep: 16
    Location: Niceville, Fl

    JimS Junior Member

    I'm going to put all new lumber supporting the motor mounts, I left them in temproray so I could build a jig to insure I get them positioned correctly. They are pretty much toast with all the rest of the wood in the boat. Thanks for all the great advice

    Jim
     

  13. tunnels

    tunnels Previous Member

    It that you deepth sounder sender unit ? Would be adviseable to pluck that out as well and repossition so its level in the boat and get a better reading and new sealant when you remount it !!:p
     
Loading...
Similar Threads
  1. Moonshine
    Replies:
    7
    Views:
    2,124
  2. massandspace
    Replies:
    7
    Views:
    330
  3. bajansailor
    Replies:
    13
    Views:
    531
  4. massandspace
    Replies:
    2
    Views:
    569
  5. Mark C. Schreiter
    Replies:
    4
    Views:
    547
  6. vroomZOOM
    Replies:
    8
    Views:
    1,038
  7. Cashinhand2
    Replies:
    13
    Views:
    1,245
  8. Ronjon
    Replies:
    55
    Views:
    4,077
  9. tuna_fan
    Replies:
    5
    Views:
    984
  10. Outwith Jack
    Replies:
    10
    Views:
    1,200
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.