88 Bayliner Trophy 1710 - wet foam and ...?

[Arawak]

Dont know if it will help, but her is what my 68 glaston looked like after rebuild

Nice work! Are those 1" (two layer 1/2" ply) stringers?

 

[Woodonglass]

Not sure you understand the meaning of "Binders" While it's true that 1708 is compatible with Poly IMHO and many others it is just a waste of resin. CSM offers nothing to the mix. It has very little strength since it's fibers are not woven. As you say it can add to the bulk by soaking up more resin and it can smooth over rough surfaces but it was created for poly so that the styrene could actually MELT the fibers so the could "BIND" the molecules of the polyester resin toghether. Epoxy has these molecular "Binders" chemically formulated in the mix and thus does not require CSM to make keep it from becoming Hard and Brittle once it cures. I totally agree that 2 layers of 8 oz biax with NO CSM will yield a much stronger layup than one layer of 17oz biax and I think it's easier to wet out too!!! But again, I would never use CSM with epoxy. I think it's a total waste of resin and a mis-use of the product. But Hey, I'm just and Old Dumb Okie and Not a Pro Glasser!!!

 

[Arawak]

Wood, I think you need to re-read the details of my earlier post on where I use 1708 vs DB1700 (or 12oz in this case).

To summarize, 1708 vs DB1700 can be useful with epoxy:

• to build up thickness quickly, like in a transom skin
• to provide some leveling for the first layer when bonding to an uneven surface

Neither of us are pro glassers, but at least some pro glassers use it in some cases.

 

[Woodonglass]

As you can see in Post #82 I referenced both points. 1708 is "Compatible" with Epoxy but, CSM was not intended or Created for use with Epoxy. It will do the things you state but if I want to add bulk I want to add strength too and CSM will not do that. You can use it, all I'm saying is I think there's better ways and materials. But again it's just my opinion and it's worth exactly what you pay for it.:lol:

 

[DeepBlue2010]

I agree with WoG 100%. Not just because XYZ company said you can use it or an ABC designer use it, it means it is the right thing to do. FDA allowed pink slime in our school meals, doesn’t make it right either. Chopped Strand Mat has its uses but building thickness in a structural element like the transom should not be one of them and I certainly would not use it for this purpose.

When I was researching the subject, and based on what I read here in iBoats and in some books, I summarized the use of CSM in boat building specifically - mold building is different story – for myself to be in one of the two following scenarios…

1- As the first layer between structural fabric and the core (plywood, balsa, etc.) to promote core adhesion and prevent De-lamination. Delamination is a Poly resin problem better solved by prepping the wood (stature it with resin first) before using any type fabric. This problem is not an issue when using Epoxy resin because Epoxy – in its own right – is a very strong glue.

2- As the first layer between structural fabric and finished surface to prevent pattern telegraphing through. In some boats, you can – if you look carefully – see the patterns of woven roving through the gelcoat.

A major disadvantage of using CSM in general is its thirst to resin and as a result, its tendency - specially in the hands of sloppy and/or rushed worker - to generate a resin rich laminate which is weaker than a laminate with only the desired amount of resin.

Finally, please understand that we are putting our collective experience at your disposal to make your own best decision, we are not trying to make it for you. It is your boat and you can do what you want. Best of luck

 

[jc55]

I agree with WoG 100%. Not just because XYZ company said you can use it or an ABC designer use it, it means it is the right thing to do. FDA allowed pink slime in our school meals, doesn’t make it right either. Chopped Strand Mat has its uses but building thickness in a structural element like the transom should not be one of them and I certainly would not use it for this purpose.

When I was researching the subject, and based on what I read here in iBoats and in some books, I summarized the use of CSM in boat building specifically - mold building is different story – for myself to be in one of the two following scenarios…

1- As the first layer between structural fabric and the core (plywood, balsa, etc.) to promote core adhesion and prevent De-lamination. Delamination is a Poly resin problem better solved by prepping the wood (stature it with resin first) before using any type fabric. This problem is not an issue when using Epoxy resin because Epoxy – in its own right – is a very strong glue.

2- As the first layer between structural fabric and finished surface to prevent pattern telegraphing through. In some boats, you can – if you look carefully – see the patterns of woven roving through the gelcoat.

A major disadvantage of using CSM in general is its thirst to resin and as a result, its tendency - specially in the hands of sloppy and/or rushed worker - to generate a resin rich laminate which is weaker than a laminate with only the desired amount of resin.

Finally, please understand that we are putting our collective experience at your disposal to make your own best decision, we are not trying to make it for you. It is your boat and you can do what you want. Best of luck

Very informative and well written...Thank you. I got some good points out of that.

 

[Arawak]

A major disadvantage of using CSM in general is its thirst to resin and as a result, its tendency - specially in the hands of sloppy and/or rushed worker - to generate a resin rich laminate which is weaker than a laminate with only the desired amount of resin.

I'm aware of this, and it's a good point.

Finally, please understand that we are putting our collective experience at your disposal to make your own best decision, we are not trying to make it for you. It is your boat and you can do what you want. Best of luck

I may not always agree with everything written here, but I usually do, and I appreciate the benefit of that experience.

 

[Arawak]

After watching the misery that was El Classico today, I went window shopping for plywood at Home Depot. Found some decent G1S (ACX) douglas fir ply in both 1/2" and 3/4. Have to really pick your sheets... 3/4 of the stack will have voids, and then you hit a section with 3 or 4 great sheets. Didn't buy any today, but I always enjoy the looks as I unload a stack of plywood to get two particular sheets.

On to the workshop (Dad's place is on the other end of town) to review the progress made in my absence and make some progress of my own.

Dad has put the bracing in place to support the hull. Everything is quite rigid. He's also made a template for the curved part of the stringers... they are 6 3/4" high for most of the 12" length, and then taper away at the bow. He's also set up a long flat area for Isabel (she says I have to call her Izzy) to glue up the new stringers.

So, I cut out the back 12" of the stringers, so that I can grind down the hull and transom. This involved removing four 6" squares of 1/2" plywood, two of which had been glassed on the hull, and to on the inside of the stringers. I'm guessing they were for screwing stuff into? The wood was completely soaked.

I donned my anti-itch gear, breathing apparatus, and eye protection, and took a 40 grit 4.5" sanding pad to the hull. Made a LOT of dust. Most of the tabbing is ground out now, in preparation for putting the new transom in place. Have maybe another hour of grinding still to do, then some cleanup sanding. No pictures, I'm afraid... there was so much dust that everything came out hazy. Will take some tomorrow when the dust has settled.

 

[Arawak]

Dust has settled, was able to get a photo. You can see where I've cut the last 12" of the stringers and started grinding out the tabbing. Discovered a sodden slice of wood filling the chine, with glass over it. I'll spray some foam in the channel it filled, then cut it flush before I glass over it. There will be a layer of glass down on the hull after I'm done grinding, maybe even two.

Had a nice piece of 3/4" Douglas fir plywood leftover from a couple boat projects ago. It was just big enough to make both pieces needed for the replacement. The original transom was a 1.5" thick almost square slab from the bottom of the stringers to the top of the hull. A 3/4" thick triangular piece of dimensional lumber sat under it. The new transom will replace both pieces with a uniform 1.5" thickness. This will allow me to tab it into the hull as well as the stringers.

So here's where we stand:

 

[Arawak]

Brought the transom pieces home for Isabel to glue up, but discovered I have no wood flour or cabosil here to make glue. Must all be at dad's. Ah well... Tuesday night.

Here are the two pieces:

 

[Arawak]

Tonight Isabel and I glued up the transom. I had her mix up the epoxy on the scale, then paint both faces. I helped a bit with a spreader.

Then we mixed up some glue (epoxy+wood flour+milled fibers) and spread it evenly. Two pieces together, and a couple batteries and a leftover case of tiles to maintain the pressure.

Not really much of a transom, for a 17' boat....

 

[Arawak]

Just placed my order for epoxy, fiberglass, and a few other things. With shipping and taxes it was over $700. Hopefully it will arrive by the weekend.

 

[kcassells]

EEEEEEEEEEpoxy la la la la....I think there is a song that goes with that...Valarie....
Welcome to the game of boat rehab. I'll be a taggin along with your permission. Sure wish my better half would jump in. But ...hmmmm let me think about that.

 

[Arawak]

Ok, I was wrong. Apparently I can't tell the difference between foam and wood stringers :facepalm:

Cut out the rear section of one of the stringers tonight and discovered that the interior was (soaking wet) dimensional lumber, not foam, not plywood. Never seen wood shavings on a drill bit look like that, but I probably should have used a bigger bit. In the end, it makes no difference, since I'm replacing them anyway. Will likely do the junior stringers too.

Here's a section, with the fiberglass peeled back (top of the stringer is in the middle of the photo) --

 

[Arawak]

Lots of grinding tonight, tons of dust. Took a photo when I got there... Dad had beveled the transom we glued up and fitted it in place:

 

[Arawak]

Discovered an easier way to remove the tabbing than grinding. Once the stringers are cut out, leaving the stubs of the the tabbing, a broad chisel and hammer driven between hull and the seam can delaminate it with not too much work. There's still some cleanup sanding to do after, but it sure beats grinding the stuff out. Shows you how poorly polyester bonds to cured polyester. Here's a section:

Tomorrow Dad will add extra support under the hull before I remove any more of the stringers. I have to go over and switch my all season tires out for the winter tires... the joy of Canadian winter... so I'll probably take out the rest of the stringer I started on tonight.

 

[jc55]

That's what I do. I do all of the chisel work and in many cases, you can completely work all of the tabbing off. I might have an hour of grinding on each of my boats but may 8 hours of chisel work on each one. IMO, I only grind where I will be glassing since there really isn't any chemical bond to speak of.

 

[studioq]

Ok, I was wrong. Apparently I can't tell the difference between foam and wood stringers :facepalm:

Cut out the rear section of one of the stringers tonight and discovered that the interior was (soaking wet)...

Yep - I had a few of those surprises too.. Made some assumptions that came back to bite me later on.. Only way to learn I guess...

 

[Arawak]

Good afternoon for me. Went over to Dad's and got the winter tires on, then we went plywood shopping. Home Depot had a stack of fir G1S (ACX), we went through it and found a pretty one only about 4 or 5 down. Dad will rip in into 7" strips, which Isabel and I will laminate into two stringers. Tonight or tomorrow Isabel will glue up some scrap plywood with Titebond3 and then I'll let her decide whether we use TB3 or epoxy to do the stringers.

I spent about an hour with the sawzall and then my new favourite tool (bottom right). Got the rest of the stringer and more old glass out in that time than I did in 3 hours of grinding last week. Can't believe this is my third resto and I'm only just discovering this method now. :embarassed:

 

[Arawak]

Sorry, no boat pics today.

This weekend I cut out the rest of the stringers, and went to work with the wrecking bar, ripping out the old tabbing. Hull is getting pretty thin. Dad is adding more support underneath just in case. He also cut out out the new and improved transom. The stern angles forward slightly starting at the inner stringers. The new transom extends past these all the way to the second stringers, and so will have a slight curve to it. I'm going to have to laminate 3 layers of 1/2" in place on the boat, to accommodate this.

My nauticus protroller smart tabs came today. Only problem is that the stern is not flat top to bottom, it "bubbles" out. Hopefully I can figure something out.