99 Larson 186 SEI Ski-n-Fish Re-Deck Project

[zool]

I use west fillers because im used to mixing them for different applications and i can grab them locally, but I use USC's laminating resin, which works great and is cost effective......keep in mind when choosing poly vs epoxy that poly is subject to hazard shipping surcharges, epoxy is not. You also use less epoxy to obtain similar strengths and less is more (to an extent) when wetting out cloth, so the cost difference is less than what some think.

 

[QuickPuppy]

Thanks for the opinions guys. Hope to have a bit of time over the weekend to get a finalized materials list together.

 

[QuickPuppy]

Well, I’m back! Finding time to do this project has proven to be extremely difficult but I have made progress...

I was able to remove most of the foam from inside the stringers. I used 2lb expanding foam to refill them and it appears to have worked well.

All of the old PB and staples have been ground off of the stringers.

I cut foamboard templates of the deck and fitted them.

Managed to finally remove the last piece of rotted deck from underneath the bow seats. Not a fun job when the cap is still on.

Purchased 3/4” marine ply for the new deck (which I now realize was probably overkill but it’s too late now.) Traced out the pieces using my foam templates.

The hardest parts to fit were that triangular piece under the bow seats. (Because of clearance problems under the bow pass through.) The main deck area around the captains chairs and ski locker also took a lot of trimming to get it to lay flat on the stringers.

I have this week off so I hope to start glassing today. I decided to go with Poly resin, CSM, and 1708.

How much thickness does the waterproofing layer of 1.5 oz CSM add? I’m thinking I probably need to trim all my deck boards to allow for that extra thickness.

 

[JASinIL2006]

How much thickness does the waterproofing layer of 1.5 oz CSM add? I’m thinking I probably need to trim all my deck boards to allow for that extra thickness.

I don't know the source, but when I was planning my layups the number I had for 1.5 oz. CSM was .045". From what I recall, I think that was about correct. If I can dig up the source, I'll post it.

 

[QuickPuppy]

Thanks Jim. Looks like that’s about 1/16” per layer. I’ll caliper it after... .741” before.

 

[QuickPuppy]

All you guys weren’t kidding when you said that CSM will soak up some resin! I kept having to make more after it would only cover a third of a panel.

Any tips on on getting a smooth finish with the CSM or is that done by sanding or fairing later? The current finish is pretty bumpy.

Also can’t seem to figure out how to get the CSM to wrap around the edges of the panels. It keeps either popping back up or making an air bubble on the top of the edge. Which leads to another question... should I be glassing the edges since they will all be PB’d and/or tabbed later anyway?

Lastly, if I should not be glassing the edges, should the CSM be cut to fit exactly or should I trim off the extra after the resin is set? It’s the resin that is waterproofing and the combo of resin and CSM that is giving strength, right? Therefore I wouldn’t think the edges really need covering with the CSM. Thoughts?

 

[QuickPuppy]

[No message]

 

[eggs712]

I always sand the edges before glassing, it helps!

 

[Grub54891]

Just trim the edges, any pb and tabbing should seal them up well. You "wet" the edges where the tabbing goes anyway.

 

[JASinIL2006]

On my transom core, I wanted the extra protection of complete encapsulation with CSM, so I wrapped the edges. I suppose PB could have the same effect, but I didn't want to take any chances on leaving voids that might provide a home for water, should it get in (heaven forbid!). Also, I found it to be good practice for covering edges, since the transom core was out on sawhorses and I could get at it easier. Better to learn on that than when you're on your hands and knees in the boat...

Sanding, or even better, routing a radius on the edge will make it a lot easier to wrap the CSM, if you decide to do that. To get the CSM to lay down, there are at least a couple of approaches. One way is to just baby it with a bubble roller, going over it until the resin really kicks off. Alternatively, you can wrap the edge with plastic cling wrap and that will hold it down nicely, too.

What you show in your pictures is about as smooth as CSM gets, or I should say, it's about as smooth as mine ever was. For surfaces you want smoother, plan to cover with a finer cloth and/or use some fairing compound. I did both on my deck.

 

[QuickPuppy]

Cool... thanks for the ideas. Just finished with the CSM on the bottoms of all my deck panels. Got everything cleaned up and remembered that the ski locker hatch and rear center panel support needed it on both sides. Time to trim off all of the extra and get back to it.

 

[QuickPuppy]

Got everything trimmed up. Hopefully going to install the deck tomorrow.

 

[QuickPuppy]

Will 3m micro-balloons work for making PB? I cannot find cabosil anywhere around here.

 

[JASinIL2006]

I think microballoons (if phenolic) are for epoxy. Glass balloons are OK for poly resin but aren’t very strong. Not the best for PB, IMO.

 

[QuickPuppy]

Didn’t get the deck down today, but did finish final fitting of all the panels. Needed the cabosil to make PB to glue it down. Finally found fumed silica at a place an hour from here. $12/quart. I get the idea that amount is probably not going to go very far. For those of you who have made PB for fillets, how much were you using of 1/4” chopped strand, cabosil, and poly resin?

 

[Woodonglass]

This tells you how to make Peanut Butter...

A good ratio to follow is 1 part resin and hardener, 1.5 parts of Cabosil and 1/4 part Chop Strand.
Using the Metric system 1000cc of Resin/Hardener, 1500cc of Cabosil and 250 cc of Chopped Strand.

 

[JASinIL2006]

That’s pretty much how I made mine. After you make a batch or two, you get a good feeling for how much cabosil and chopped strand to use. I found that stuff harder than the dickens to sand. No comparison between fairing compound and PB in ‘sandability’. (I made up that word!)

How soon do you need the cabosil?

 

[QuickPuppy]

Realistically probably not for a week. Got asked to work an extra day.

 

[QuickPuppy]

So by that recipe, two quarts of silica is not going to make much at all.

 

[Woodonglass]

Nope but Cabosil is Cheap! U.S. Composites is a great source. 4 gallons for $30 including shipping.