Please critique my 23' CC Rebuild plans

[flyingfrizzle]

Also don't be afraid to search the site. Our search function sucks. Use the google search bar and search for what you like and just add this to the end of it and it will search this site only:


site:http://www.classicseacraft.com


There were a lot of good post/threads 5-10 years ago with wealth's of info. Read the archives and you will know more about seacraft hulls or hull repair than you ever wanted to. If I had a penny for every post ive read or studied I would have all my hulls restored and running....

[take a potter]

Thanks for all the input. So Flyingfrizzle, if you were making a bracket with vinyl ester would you use csm between each layer of woven Ie. 1208 or 1708 vs 1700? And more importantly what would you do between layers of plywood in the transom of the bracket?

Over the years I have read a lot of those old threads, I'll go back over them again, unfortunately we lost most of the pictures when photobucket went south.

[flyingfrizzle]

Yea, Photobucket sucks for that deal. They should of grandfathered in pictures uploaded prior to the date of screwing people and holding their uploads for ransom.


Layers between the plys in the transom of an hull or bracket rear-


With VE and poly I normally add two layers of 1708, one facing one way and the second opposite laying the csm layers on the ply and the biax side against each other. If I don't do that I will just add stright csm. I like having the csm on the wood as it will wick the resin out of it. The csm will hold higher percentages of resin and have more to give to the wood long as you wet it out well so it don't leave dry spots after the wood soaks it up. Far as strength this really don't add much to any. Honestly doing like they did at the factory and stapling the sheets together will work just fine. The outer and inner layers are what make the strength. Think of an I beam. I just do it mainly to saturate the wood as much as possible with resin. I also thin the resin with styrene or acetone to get the resin viscosity down so it can soak in easier. I normally buy thin voc resin to start with or infusion resin as you can hand lay it up and it wets out great. Stuff that needs thicker resin I just add cabosil like on verticals that want to run. VE and poly harden fast enough that you can just keep working it to it kicks and then it will stay in place anyhow. So whether or not you do a center layer between the core or not I don't think it matters just have good thick layers sandwiching the core in the middle. It may add some compression strength for you bolts but there other things you can do to aid in that. Using marine ply I would hot coat it with super thin resin with minimal mekP 3-5 times until the wood wont take it any longer. Something else I started doing was fully encapsulating the wood transom cores prior to installing them in the hulls. Lay up the inner side with 75% of the lay up and add a little to the back side and make sure it is wrapped 100% around the core. I cut the ends on angles to make the cloth to lay down and sand the wood so it is a smooth transition for the cloth to lay on. Once I get The entire core sealed up with VE or poly I bond it to the old hull skin with epoxy resin. In the back of a bracket tub you can lay it up wet on wet and use VE for all of it. On older 30 year hulls the epoxy gives you that strong secondary bond to the old glass where as on a bracket transom you can do it in the "green" time window for a primary bond. Now after I have it bonded into the rear of the hull/bracket tub I will add filets around the inside edges and then lay two sheets of 1708 over the inner side lapping it on the hull sides to tie the entire core to the hull. After that plenty of tabbing. You can do this with VE or the epoxy but like mentioned I generally only use epoxy when bonding two cured pieces together as an secondary bond unless there is epoxy there already and that forces you to do epoxy on top of the previous epoxy. By sealing the core 100% prior to installing it there is no to little chance of water getting into to the wood ply unless you drill holes in it which you would want over drill to seal with resin when you did. Less likely for air voids and any gaps can be filled with thickened resin.


Far as the bracket-


Laying up the tub I have used 1708 mainly because you have to build up so much thickness and 1708 builds thickness faster. You could start with Gel coat or primer then 3-5 layers of csm and do all 1700 after that but you would really need to add a lot and pull an vacuum on it to insure the layers get bonded well together. Puncture resistance, over all flex, strength and crushing resistance where the bolts go have to be observed also. I do stingers in the tubs and add core to spots of the swim platform as well. I haven't cored an entire tub but modified a dusky bracket one time that was cored with balsa wood. It would be in your favor to make the bracket light but that's hard to do with fiberglass. I have built them from aluminum also and they are lighter for sure. Maybe some others with bracket experience will chime in as I would like to know what they have done and what works far as lay up thickness without flexing. I tend to over build stuff lol.

[take a potter]

Thanks FlyingFrizzle, I think I will go with 1.5 oz csm on each side of all wood, and use vinyl ester. I read somewhere I think on one of daytrip01's treads that 3 layers of 1700 are stronger than three layers of 1708 and weigh less. So I will try and build strength with 1700. My whole plan was based on epoxy, but I think I am getting more comfortable with vinyl ester. Thank you for all your, along with everyone elses input.

Where did you find vinyl ester in 55 gal drums? I have search in my area and can't even find gallons.

Got motor off, t-top off and console out today. I will start a build thread shortly.

[flyingfrizzle]

Originally Posted by take a potter

Where did you find vinyl ester in 55 gal drums? I have search in my area and can't even find gallons.

shortly.

I got my VE drum a long time ago from a local from a boat builder, He was building a hard top for a sportfisher and ended up with more drums than he needed. I got it on a discount. It was a low viscosity VE infusion resin as he was infusing the hardtop but I have really liked the thin resins for fast wet out. Matter of fact that's about all I will buy now are thinner viscosities when it comes to resins even epoxy. What I had was an AOC product but there are a lot of different types out there. I have gotten other types from local boat builders, Sometimes if you show up with a few clean buckets they will sell you whatever you want out of their drums or either order you one. Price around as there was a new repair shop that opened local to me and I priced a drum of general poly from them and they wanted an arm and a leg. Some shops will look out for you and sell at their price and some will mark it up 30%. I would check with some local boat builders local to you or open a commercial account with an distributer that will deliver. A drum will easily meet minimum order requirements or cost normally.


The VE resin came from Composites One which distributes all over the US, most local builders to me use them for all kinds of marine supplies as they carry lots of stuff


https://www.compositesone.com/people/about/locations/


I buy my epoxy from US composites and they also have VE resin. They will sell in kits from 1 gallon up to 5 gallons.


http://www.uscomposites.com/polyesters.html


You probably wont find VE local on a shelf (I wouldn't want some old resin that has been sitting on a shelf awhile no how) but you should be able to order it from a lot of locations.

[strick]

Composites One usually sells vinyl ester but they have it in 55 gal drums if you want 5 gal pails they will do that but you have to wait till they pour it for you...if you are doing a big project (which you are) consider opening an account with Composites One for all your resin needs...other stuff get from wherever you can find it. I never used anything but 1708 and heavy matt (for the first 2 layers) on the brackets I did just be sure to alternate the 1708 so the fibers are not going in the same direction all the time...

another thing to consider that I don't see mentioned ever is the type of washer used to bold the bracket to the transom...Square washers (plate washers) are far stronger then round washers so I usually had some ss 1/4" thick 2x2" washers made up (welding shop) for the bracket...you probably can find these already pre made if you search.

strick

[take a potter]

I spent quite a while on the phone this morning with the regional rep from Composites One. He is going to work on getting me a price for a 55 gallon drum of resin. He is based out of North Carolina, and hopefully he can get some within a 2 hour or so drive from me. Funny that you both mentioned them today.

[flyingfrizzle]

Originally Posted by strick

another thing to consider that I don't see mentioned ever is the type of washer used to bold the bracket to the transom...Square washers (plate washers) are far stronger then round washers so I usually had some ss 1/4" thick 2x2" washers made up (welding shop) for the bracket...you probably can find these already pre made if you search.

strick

Search for 316 ss unistrut washers. We use them all the time in industrial electrical mounting hangers. They are common with 3/8" and 1/2" holes and measure 1 1/2" x 1 1/2" normally.


For backing brackets and outboard bolts I just normally use 4"x 1/4" aluminum flat bar cut down to size.