CPES v. West

I'm replacing the sole on a 1984 Century Bowrider. I know the subject has been addressed many times but I still have a couple of questions:

-The pros and cons of CPES and West products
-Is it better to place the new sole right on top of the old stringers or build the stringers up 1/2" and place sole on top of the remaining edge of old sole?

Thanx in advance. I've learned a ton on this site.

Regards,

Heyboer

 

West System is now offering a penetrating epoxy (I think) and I would imagine, they have competitive performance with Smith's CPES (also a penetrating epoxy). West System is the industry leader and much, if not most of the research available on epoxy performance, is a result of their in house testing. It seems very unlikely they would market a product, to battle the strong arm lock, that Smith's CPES currently has on the penetrating epoxy arena, with an inferior performing offering.

In your boat, there are no cons to using CPES or West's penetrating epoxy. You have a polyester built boat with solid and plywood structural elements, which are also coated to some extent with polyester. Polyester's ability to bond with wood is quite poor compared to epoxy, so you'd loose nothing by using epoxy.

In most boats of that era (early - mid 80's) that require a sole replacement, they usually also need new stringers and transoms too. If your stringers are solid, then bond directly on top of them (use laminating epoxy). If you have questions about their health, then cut open some test areas or probe around with a scratch awl and see what you have as far as solid wood. If it's like most of that era, the wood will be soft and punky, requiring replacement (I know it sucks, I do it all the time). Most of these boat structures fail because of poor (if any) drainage. These boats often trap moisture between the liner and the hull, with no way to get to the transom drain or bilge pump. It's just a matter of time before rot eats up the wooden elements of the structure.

I often solve this problem by replacing the stringers with wood (again), but with weep holes to permit the moisture to drain aft. Then I build a new, usually lower on the transom, sump and transom drain, so that the moisture under the liner can exit the boat, when you have it on the trailer, bow up and un-plugged.

 

West System

Boy, I just saw a chart by West somewhere in my Web-crawling that showed their tests of "Penetrating Epoxy" VS their regular resins, and various "penetrating-followed-by-resin" applications. They measured how much water was later absorbed.

NET: Penetrating Epoxy alone lets lots of water penetrate later. Following it with regular resin makes it a LOT better.

Anybody remember where the heck that was?? I'd like to put it on the "Boatbuilding Materials" Wiki...

I'm drowning in information trying to float my boat

 

I put mine on top of the old deck. I left 4" of the old deck and cut the new deck 2'' shy of the sides, with beveled edges. That left a 2" wide, 1/2" deep channel around the edge of the deck where all the water goes as the boat rocks back and forth and keeps the deck less wet while cast netting.

 

Found it! CPES VS WEST

I put a copy here:
http://www.boatdesign.net/wiki/MaterialsForBoatbuilding#Protecting_Wood_with_Epoxy

I asked WEST and got an email back that the chart is in their "Blister Repair Manual", which is not on the website. I'm getting a copy sent and I'll abstract some more from it into the Wiki.

 

CPES v. West on my Century

Thanks all for the replies. I am worried about the stringers and transom, as rebuilding these areas might be over my head (what the heck do you do with the I/O and stern drive?). I haven't taken out the entire sole yet, but the stringers I have access to seem pretty solid according to my "knuckel test". Foam seems hard and dry. This boat has a ski locker and it seems to drain well (almost swamped it two years ago with a bad bellows). I think most of my sole rot was due to age, carpet, and a rubbery cover that probably didn't breath at all.

I am going to use West products as they have a store not that far away.

Heyboer

 

I/O & Sterndrive.... remove them.
You'll need some kind of hoist... ingenuity starts here

 

Thanks again for all replys. Par, you have the patience of a Saint with all the time you spend helping out the unwashed masses (me!). After giving the stringers a real good going over I have only found one that needs attention. It's at the stern, to the outside and only about 38" long (the length of the engine compartment). The engine does Not sit on this stringer, and there is another 38" stringer between the bad stringer and the engine compartment.

Anyway, I don't have any kind of tool to cut the old stringer out and even if I did I wouldn't be comfortable cutting and grinding right on the hull. That scares me to death. The old stringer still has some strength to it, it glassed on the sides, and I am thinking of leaving it in and putting a new stringer, epoxied to the max, right next to it. Any thoughts?

Other that that I am pretty happy with the Century. The foam is hard and only a drop or two of water was resting on the hull when I dug out some foam. I know the foam is for flotation, but does it add much strength to the structure? Sure seems to.

 

Yes, the foam can add to the strength of filled areas.

You can sister (side by side repair) the bad stringer. Grind back to solid, good 'glass on the old tabbing, over the old stringer, lots of thickened epoxy and fabric, trying to error on the too much, then not enough side, of the "how much do I use" thingie.

A boom style engine hoist will snatch that I/O off the boat. An over head mounted come-a-long, will do in a pinch

 

If you need to remove the engine without hassle and can spare $100 Canadian.... Just rent a truck crane. It only took 30 min to get two engines out. That's what I did.

As far as the outdrives... I payed a marine mechanic to take them off, however, after purchacing and reading the manual, I could have done it myself.

Your boat may be a bit small to require a truck crane, but it might save allot of hassle; Especially if you don't own a hoist. Another idea might be to make a rolling frame with a rope and pulley system, but good luck with that, and don't crack your head!

All in all, I am VERY glad I removed he engines - this has saved me from allot of headaches.

Cheers!

 

I appreciate all the good advise, but I punted! I keep the boat in an alley. Prop against a fence and tounge in the roadway. While I'm not afraid to tinker with an engine and have done many things to past cars, I've never even seen anyone pull an engine and givin my logistical challenges I was very apprehensive. The cost of renting a hoist (twice) and getting an engine alignment tool ($135 b4 shipping), multiplied by the chance of screwing something up seemed too risky. A couple of kids playing baseball 4 times a week; a 90 year old house to keep up equaled moving at a glacial pace and maybe not seeing water all year.

So I contacted Gonzo from this website and took a ride up to the land of cheese. I feel I left my boat in very good hands and his rates were reasonable.