need some guidance. stringers & transom

[tartuffe]

I used 2 layers of 3/4" marine ply.

First layer: In order to get that bend I cut 2 score lines about 3/8" deep at an angle, makes conforming to the hull much easier.

The score lines are on the side that faces the bow, not the side that will attach to the existing transom skin If you look closely at the transom you will see how the curve in the transom comes up at about a 60 degree angle on both sides about a foot on either side of the drain plug hole. Your score lines should follow that line.

I hope this makes sense, have plenty of clamps available.

Do a couple of test fits and try a dry clamping run.

When you are ready to do it for real, trowel a heavy layer of thickened resin on the existing transom skin and trowel a layer on the ply that will touch the transom skin and sandwich the thickened resin to the skin, clamp it and leave it overnight.

Second layer doesn't need score lines, again put thickened resin on layer you already clamped the prior night as well as the layer you are about to place. Sandwich together and clamp, lots of clamps.

I made the mistake once spreading a heavy layer of unthickened resin on the wood prior to troweling out the resin, the thickened resin won't stick if you do that and will ooze off the wood. You can use a very light layer of unthickened resin but don't get carried away.

[brywheat]

Thanks Tartuffe!!

Few other transom questions for you...
How thick do you think it needs to be to support a bracket?
Only the first piece gets scored correct?

Thanks a million, everyone on this site is great with great info

Loving the V20 community!

[brywheat]

Here are some pics..
Admin feel free to delete the orginial thread I started in the General Forum

Thanks again for all advice, Im sure I'll need more

[tartuffe]

Yes only score the first layer, once it is fully adhered to the outer skin it will be strong enough to torque that next layer in place. Even with all that torque it still will not fit absolutely snug against your first layer, that is where all that thickened resin you troweled on comes in handy.

I used that blue styrofoam board to cut my templates, it works really well.

There is a trade off regarding how snug you want the wood to come to your gunnels in the corners of your transom. I left enough room that I could easily get the thickened resin all the way into the corners. I left about an inch. It was very easy to make sure I had zero gaps in my corners but it did eat up ALOT of thickened resin.

Regarding brackets, I have no experience so I can't comment there. Brackets are sexy as hell but I opted not to put one on when I did my restore. It just didn't match my needs for the boat.

[brywheat]

Thanks again Tartuffe

Off the next two days, hopfully be able to get to Harbor marine and pick up some supplies.

What kind of ply did you use Tartuffe?
Im thinking of going cheap and using Fir, however Ive been told Okume BS1088 Joubert, Meranti BS1088, or Meranti BS6566, are the have trade-offs for the cost. The BS6566 I've been told is best for a structural/ resin fiberglass bonding and it will bend easier to match the transom curve and is stronger, the $20 etrxa per piece may be worth the trade-off.
What would you use??

[tartuffe]

I used marine grade Baltic birch, it was some high dollar stuff but all of those you mention are all quality products from my research but I have not used them. Sounds like you are on the right track.

So do you plan to save the cap or are you going to transform her into a center console?

I used 1/2" divynicell foam for my floor core and hatches. Really great stuff to work with. May want to research those foam cores and consider them for your deck. My hatches alone weighed 80 lbs before the recore and 33 lbs after and solid as a rock.

[tartuffe]

One thing I will say about the wood you select, I had my boat at my friends dealership in his pit doing some fine-tuning on the engine. It is incredible the amount of force that is placed on that 1-1/2" of ply and maybe 1/4" of fiberglass. I see guys using everything from the products you mentioned down to bottom-dollar plywood.

Once it is all done, and the 600+ hours invested are to be enjoyed, never worry with if you should have spent the extra money on the wood. Skimp on light packages, pop-up cleats, rod holders and all the bells and whistles as they will end up costing far more than what you spend on the structural components and you can change those out later as they start to show their age.

[brywheat]

Tartuffe

That raised another question. If I decided on the full transom/ bracket. . How thick should the transom be? I'll be replacing the stringers to and plan on tabbing in knees which will rise from stringers to the top of the transom. I'm either glassing in insulation for a fish box or making a livewell.

[Starzofchaos]

Have you thought of using Divinycell 5lbs or Core Cell 5lbs foam core instead of the wood? Its a little bit more expensive, but the amount of weight you will save and the thought of it never rotting out...

http://www.merrittsupply.com/default.aspx

[tartuffe]

I used divynicell for my deck. Its a great product but while it is lighter than wood you will use far more fiberglass and resin in such a crucial structural application so the weight savings will be offset and it will be more difficult to use compared to the wood in the stringers. The transom wouldn't be a suitable application either since the foams are crushable.