Jasona12380 1969 FB Rebuild

[Fish Head]

Since your asking I would grind until you definitely get to decent glass for best bond. If you get a little to thin with wall thickness I would not hesitate to layup a layer or 2 of 1708 to glass before you install coosa.

[RickK]

I second Fish Heads comments. After grinding, the first thing to do is cut a 12" piece of PVC and glue it (thickened resin) onto the bottom and to/through the original drain hole. Here is a link to where I explain the thought of the PVC pipe
http://classicaquasport.com/smf/index.php?topic=13148.msg133124#msg133124

Here is a link to where I show what is actual problem
http://classicaquasport.com/smf/index.php?topic=13148.msg133556#msg133556

Here is a link to Hawgleg's rebuild that shows the PVC pipe installation to keep a drain at the new low point of the boat
http://classicaquasport.com/smf/index.php?topic=13148.msg134262#msg134262

Next is to mix thickened resin and lay in fillets to round out the corners and sides of the transom. Next start lay up of at least 2 maybe 3 layers of 1708 to build up the transom thickness. let it harden and then lightly grind the new glass layer. Now you have a good foundation for the transom core.

[Jasona12380]

Time to put in an order for transom material.  Coosa is sold in the town I work in Hyannis Ma, I plan to buy a sheet of 1.5 inch Coosa once the epoxy arrives.  I am a little unsure on the material needed and amounts to purchase.  Below is a list of material I plan to purchase based on research from everyone on the forum and what was recommended from a friend who works at Metan Marine.  I don't mind buying extra knowing that I will use extra material left over from transom for stringers/coffin box/floor overhaul.  Please share any advise on material and quantities.  I am very new to fiberglass.  Limited to surf board repairs only.  Any recommendations are very much welcomed. 

West Systems 105 Epoxy Resin 4.35 gallons
West Systems 207 Special Clear Hardener 42 oz
West Systems 209 Extra Slow Hardener 42 oz
West Systems 406 Colloidal Silica Adhesive Filler 5.5 oz
2x 1705 x 50 biaxial
Sheet of Melanine board
2 1x8 rollers
5 mixing pint cans and 5 mixing quart cans

[RickK]

If you're only working on the transom and surrounding area I think you are ordering too much epoxy - good thing is it doesn't go bad like poly.
I would think you wouldn't need more than a gal for the transom.
As for the 1705 - are those rolls of 50" wide 1705?

[Jasona12380]

Thanks Rick, I downsized on material. Thanks for your suggestion. Tomorrow night I plan to leaf blow the dust out of my work area and clean. Maybe make my template for the laminate. 1708 is 50 inches wide. I will open them up to make sure I have enough cloth.  Plan to get melamine board from local hardware store this weekend. Transom skin is fairly straight but still want to backer with melamine to be sure.  I plan on filling the void of the transom skin with 3-4 layers of cloth and epoxy plus 3 full sheet layers of cloth tabbed into the side hull and floor. I will put PVC pipe down before glassing, thank you everyone for that tip. 

[Jasona12380]

Grabbed my melamine board, waxed it and waiting for my co-worker to help me screw into my transom skin.  Started cutting out my cardboard template for laminate and realized I need to order more 1708 cloth.  I am going to get a 10 yard roll.  There appears to be a few different types of 1708 biaxial cloth.  Any recommendations on specific 1708 cloth for transom install?   

[RickK]

There is only 2 kinds of 1708 - one with CSM included on one side and one without
https://www.uscomposites.com/specialty.html

[Jasona12380]

Thanks Rick, I ended up going with 1700 biaxial cloth.  Finally got some work in this week.  I mixed silica to make peanut butter for the corners, 4 layers in the transom void, then covered the whole transom with three layers tabbed in.  Wish my tabbing was 12-8-4 but think it came out good enough.  After glass cured I noticed some small air pockets in the layered cloth.  They are very minor but trying to decide if I try spot injecting epoxy, grind out and layer more cloth, or continue with coosa install. 

[RickK]

I think you'll be fine. You're going to be lamming in a core and 3 more lams of 1708 tied into the hull sides. I think your pipe is a bit short though.  You'll know when you look into the bilge after you have it tilted back on the trailer.

[DanB]

Agree with Rick. During some of the grinding I found air pockets that seem to have stayed moisture free. I found the mini paint rollers are a great help with the wet out and removing most of the air pockets. Mini foam rollers are ok but the rounded tip always seems to break off during wet out. Had a few in the garage and decided to use them up. Chip brushes have helped with some of the isolated air pockets and corners by dabbing the pocket with resin during the lay up. Even then when I come back I still find them here and there.

[RickK]

Hard rollers work best to drive resin in and through cloth
https://m.media-amazon.com/images/I/61GocWXQDbL.__AC_SX300_SY300_QL70_FMwebp_.jpg

[Jasona12380]

After putting this project down for most of the summer I just got back to it.  Got my coosa installed and started to start ripping up some of the deck.  I didn't see any delamination yet but not too far into it yet.  I just fitted 4 layers of cloth last night and plan to glass in early this week.  Ran short of filler when doing the core.  I am restocked and plan to use plenty in the corners of transom/hull at the same time I tab in the cloth.  Great to be back at it!!!
 

[RickK]

Any progress is a good thing 

[Jasona12380]

Finally removing some foam.  Started with the side stringer and plan to continue on the other side tonight.  Really happy to see how well the stringers held up.  The foam was moist likely from the broken hose coming out of the anchor compartment to side hull.  It was completely rotted and failed.  Whenever there was weight on the casting deck causing the hose to take in water.  I need to order foam.  Haven't done much research so wanted to ask what density is best for this application and how many gallons should I purchase?