The bare wood soaks up the resin, 1708 soaks up the resin, w/out the CSM 'sponge' in between, the wood or the 1708 could wick resin away from the other and weaken the bond.
1708 is E-glass Biaxial (+/-45) with a 3/4 ounce chopped strand mat backing. When using Polyester resin you always use mat prior to applying cloth or woven roving to acheive proper bonding. You should use a minimum of 1.5 oz of mat before applying any cloth and since the 1708 only has .75 oz of mat an initial layer of CSM is recommended. Check the first link in my signature below for drawings and details on how to fabricate and install your stringers, transom and deck.
I ordered 25 yards of 1708 and I have a 19 foot. I will use it regardless I suppose. I'm going to add 25 yards of CSM to my order. I was thinking of making a sit on top kayak and this might be a reason to with the left over 1708. My wife says no more projects but I cant resist.
I'm sure ill be adding more resin to my order as well.
Thinking ahead I wanted to know a little on what you thought on foam. I read some arguments on pour in vs the sheets at home depot. How can I tell if my manufacturer used the old foam for structural support? Its a 1974 trihull fiberglass made by thunderbird.
The foam I pulled out was the expanding type but it was waterlogged completely. Has foam performance changed in the past 40 years or can I expect poly foam to resist water more?
Ok, I finally got a free weekend to work on my boat. The stringers are in and glassed. I must have watched frisco's videos 1000 times by now. The transom is tomorrow. Anybody know how thick it should be? The selic manual I have doesnt say anything. I have the mercruiser inline 6 if that helps. I was thinking of gluing 2 5/8 together and glassing that in. Is that too thick?
Yes, I believe it's 2" + or - 1/4". You MUST research this and find out EXACTLY what the transom thickness is for your outdrive and you must ensure that the thickness on the keyhole is uniform and parallel. It is critical in order to obtain a proper seal for the outdrive.
I have an inline 6 cyl with a pre alpha outdrive. I cant find anything on it anywhere. If I cant find it im just going to make it close to the same size it was and hope it works. Any input would be awesome.
finx. What is the model number of your engine.. too bad you dont have a Volvo. Don S on the engine side has a huge pocket full of miracles when it comes to volvo
I'm going to emphasize this again...If you want your installation to go well and your outdrive NOT TO LEAK, then you must pay very close attention to the specs on your transom build.
