Building a '93 Caravelle 1750 Classic Bowrider

[tpenfield]

Be careful on the yield estimates from the foam 'kits'. They are under optimum conditions (85˚ F). If it is colder, then the yield will be less. I would plan to be over by about 20%.

The 2 lb foam expands about 25-30 times the liquid volume and the 4 lb about half as much, etc.

 

[archbuilder]

If the hull is below 70 I usually try to warm it up with a heater. I have a shop with heat, so that isn't all that hard. The warmer it is in the winter the better yield you will get. One other thing that helps a lot in the winter, I put my foam containers in warm water to heat of the material.....nothing crazy, but if you can get the material into the mid 80s or so It will fire off a lot better, even in a colder hull.

 

[steve_h7]

I found a hair dryer could heat up the area under the deck really well before pouring the foam.

 

[Reserector_]

I was toying with the hair dryer idea already. I figured if I set it up to flow heat from a hair dryer or two, I could leave them on until the hull temp reaches 80° ish.
Hadn't thought of warming the components other than leaving them in the house. I could put them in the microwave.
Kidding about the microwave. I was actually thinking of soaking them in a warm bath.

I'm seriously thinking of adding more than the factory did. Especially in the aft portion. Like from just below the gunwale to the floor, leaving room for cables on the starboard side. It's useless space anyway.

Also might bulkhead the very front of the ski locker and foam that. Possibly some other places in the bow under the seating.

 

[archbuilder]

Just make sure you ready when you mix it up, you have about 30 to 60 seconds to mix it and pour it into the cavity. I use a plastic funnel...... pour and measure the two parts in separate cups, combine them in another cup, mix furiously and then pour into the void. I just let the foam fire off in the funnel and the mixing cup. it peels out fairly easily after 10 minutes or so. I have found that trying to clean it up while it is firing off is usually a lost battle. Just make sure you tape off any finished surfaces. Also it doesn't stick to packing tape, or for that matter to most plastic very well.

 

[Reserector_]

I got the stringers glued, gaps filled, and fillets made. I've spread more peanut butter today than a grade-school lunch lady.

 

[archbuilder]

looks very nice!

 

[Reserector_]

I didn't get much boat time today. Only managed 50% of the tabbing, unless you include cutting the fabric. If so, I'm at 57%.

Two layers of 1708: a narrow tab and then a wide tab. Laying up both layers wet on wet and working it all down tight with a ribbed roller before moving on. That keeps the fibers as compact to the surface as possible without the use of a gigantic vacuum bag. Lol.
Maybe I can finish tabbing during the week. Then there's the holiday time. Wohoo! Maybe I'll have the deck somewhat done on a week.

 

[mickyryan]

looking good, i just ran though your entire post , you are well on your way!

 

[kcassells]

looking good, i just ran though your entire post , you are well on your way!

I don't know Mick.. work looks a little sloppy don't ya think. He wont be done for 5 years and wasted all his monies.

 

[mickyryan]

well i mean err umm yeah work faster! ..... not everyone including myself can work at my previous pre heart surgery pace lol , yet! ill be back to it soon , but id say hes moving along well enough

 

[Reserector_]

For the record, I pulled this relic out of the woods on August 10th, so I'm easing up on four months.

It was a warm evening so I shook off the laziness and finished tabbing the stringers tonight. (Just over 4 gallons of resin at this point.)
So glad that part is over. All that crawling, kneeling, hunching and twisting is difficult for a buff guy like me. (Buff = big ugly fat feller). Especially right after dinner.

Next thing is to install the tank.
THEN I get to map out the floor panels using a ticking stick. Should be fun.

​​​​​​​

 

[archbuilder]

Looks good! All of the crawling around and tripping does suck! Once you have the deck in, life is easy lol!

 

[Reserector_]

The plywood along the center of the boat is not level, so I can't rest the fuel tank on that. I decided to go with PVC 1 by 2 on edge, glued to the tank. It will rest on the angled portion of the hull.
I cut some pieces to length and taped them on to do a trial fit.

This gives me a good amount of space underneath and still have enough room on top for some bracing under the deck. This tank is longer than the original, so I will lose some ski locker length, but I don't have a problem with that.

I believe the important thing about mounting an aluminum tank is to make sure that water can never get trapped against the aluminum and cause pitting. Therefore spacers get glued to the tank, not to the structure.
I use Loctite Power Grab because it sticks instantly and you don't have to hold parts in place. I built my entire camper structure (aluminum on steel) with this adhesive. It is absolutely incredible. Very much akin to 3M 5200. It will glue a turd to an ice cube.

With all of the spacers glued to the tank and no gaps showing, I added some blobs of adhesive to allow for bedding-in on the fiberglass. This should be enough to keep it from shifting around without making it impossible to remove in the future if the need arises.

The cord on the tank is merely serving as a temporary spacer.

With the tank in place, I set a piece of ply on the supports to give me a surface to map out the floor panels on.
It also allowed me to stand up in my boat and imagine it from this perspective for the very first time. It was a milestone for me. Pretty exciting.

The ski locker frame will still fit, but it has seen better days. However, the best is yet to come.

 

[froggy1150]

I am looking at your tank supports and would be afraid that if you got a few good hits that twist the hull with all that weight it could possibly cause one to lay on its side. Then you would have a loose tank under a glassed deck. I suggest square pvc atleast.

 

[kcassells]

Geezzz. Total wrongo on the gas tank install.
This conversation is old and separates right from wrong.
This approach is not a healthy fix, rather a cheap quick fix at the least.
All the materials are wrong for the install. Concept is on the money. Look into neoprene rubber which does not have a chemical adverse reaction .
It gets glued to the sides and bottom prior and to to the tin. Does not get glued to the tin.
Any who...your boat so do what you want.

 

[Reserector_]

Geezzz. Total wrongo on the gas tank install.
This conversation is old and separates right from wrong.
This approach is not a healthy fix, rather a cheap quick fix at the least.
All the materials are wrong for the install. Concept is on the money. Look into neoprene rubber which does not have a chemical adverse reaction .
It gets glued to the sides and bottom prior and to to the tin. Does not get glued to the tin.
Any who...your boat so do what you want.

Note: I will also be installing blocks above the tank, attached to the stringers, that will prevent upward movement.

Gluing the separator material to the aluminum is a method of preventing trapped water against the tank surface, as this is the most common cause of pinhole leaks that lead to failure according to my online research.

Aside from reading forms and watching YouTube, here is the ABYC standard that I referenced. The section on tank installation starts at 24.10 https://law.resource.org/pub/us/cfr/ibr/001/abyc.H-24.1993.pdf

"24 .. 10.6 All non-integral tank supports, chocks or hangers shall be separated from the tank surface by a non-metallic non-moisture-absorbent, non-abrasive material suitable for the purpose (e.g .. neoprene, Teflon and high density plastics)."

When I permanently glued the high density plastic to the tank, those components became integral to the tank as opposed to the "non-integral tank supports, chocks or hangers" mentioned above.

I'll ponder it some more this weekend and consider adding some more standoffs with 5200 in case the Loctite were to fail. I've used this loctite product to glue pvc to bare steel and later had to chisel it off, leaving bits of plastic behind. But that being said, 3M 5200 is the ultimate for this application, and I have some on hand...

 

[Reserector_]

I am looking at your tank supports and would be afraid that if you got a few good hits that twist the hull with all that weight it could possibly cause one to lay on its side. Then you would have a loose tank under a glassed deck. I suggest square pvc atleast.

Valid point. I feel really good about the bond and the stability of the supports, but I may add some more to what is there.
I will always have access to the tank through the ski locker. You can see the bottom of the tank through the bulkhead opening.

 

[Reserector_]

Today I cut all of my floor (sole) panels.

I used the "ticking stick" method and it worked like a charm. I even had a little time to glass the bottom of the two small pieces that surround the bilge.
Tomorrow, I will continue glassing the bottoms and edges. I also need to cut joiners because I have several unsupported seams. I figure I will attach them to one side of each joint, and apply peanut butter to them and the edges as I add the next sheet.
There will be a support above the tank, and one where the plywood stops just before the tank fittings to stiffen that floating edge.

Here is the stick that I made to plot the points onto a piece of cardboard.

A saw mark serves as my distance mark.

Touch it to a point along the edge, pull it back 1/16" and mark along the edge of the stick, mark at the distance cut, and make one more line to show the direction the stick was pointing.
Start at the corner and work your way around. Do not let the cardboard shift, and do not flip the stick over. Consistency is the key.

You will end up with a map that looks something like this.

Next, move the cardboard to the plywood and use the stick on the marks to make sure the pattern will all fit on the sheet, and clamp it down.

Move from line to line and make a tick mark at the tip. Later, connect the ticks with a straight edge or a flexible curve.

The floor dropped right in without trimming. Here is the fit:

It got a little weird in the bow, but I plotted each feature and the panels dropped in with very little gap.

 

[kcassells]

Note: I will also be installing blocks above the tank, attached to the stringers, that will prevent upward movement.

Gluing the separator material to the aluminum is a method of preventing trapped water against the tank surface, as this is the most common cause of pinhole leaks that lead to failure according to my online research.

Aside from reading forms and watching YouTube, here is the ABYC standard that I referenced. The section on tank installation starts at 24.10 https://law.resource.org/pub/us/cfr/ibr/001/abyc.H-24.1993.pdf

"24 .. 10.6 All non-integral tank supports, chocks or hangers shall be separated from the tank surface by a non-metallic non-moisture-absorbent, non-abrasive material suitable for the purpose (e.g .. neoprene, Teflon and high density plastics)."

When I permanently glued the high density plastic to the tank, those components became integral to the tank as opposed to the "non-integral tank supports, chocks or hangers" mentioned above.

I'll ponder it some more this weekend and consider adding some more standoffs with 5200 in case the Loctite were to fail. I've used this loctite product to glue pvc to bare steel and later had to chisel it off, leaving bits of plastic behind. But that being said, 3M 5200 is the ultimate for this application, and I have some on hand...

I found this to be a good read. Nice Deck!
https://www.yachtsurvey.com/fueltank.htm