Project "1600 Capri Hard Top" has begun!

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

Have been playing around with the results of my tests. All I can say is "%&^#@%^& " that 1708 biax is like nothing I ever used before. Compared to the 6oz -10oz stuff I used, this 1708 is more like 1/4" plate steel. Its only been about 5 hours since mixed and applied, and even if I press my thumb on it will all my weight, it does not deflect and make a dent in the foam underneath. (well, maybe not all my weight, but all I could muster to lean on a portable work bench without collapsing it.) The single layer 6oz is very firm, but will deflect under pressure, and two layers on foam will be plenty strong for making things like live wells, center consols, and partitions/walls under splashwells, etc.

I still cannot believe the strentgh of the 1708. No wonder the guy I bought it from was getting irritated when I continued to question him about its characteristics and my application. He said "it is more than enough for your top". He said three layers is typical application to build a 17-19' hull that needs to handle the pounding the open waters.

But it is heavy.

I'm happy.

BTW, its in the 80's, rather dry, and no blush showed up at all on this regular laminating epoxy. So another fear is set to rest.

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

So its been about 6 hours since the epoxy set, and I know even though I should wait 24hrs, I decided to start destruction testing on my test pieces.

1) Standing on it test: Put the 1.5" foam covered with 1805 biax on both sides on the concrete floor and stood on it (180 lbs). Nothing happended. Close inspection showed no de-lamination from the foam.

2) Standing on it test 2: Put the same biax piece on the blacktop driveway. The driveway is not as smooth and has a few loose gravel pieces. Stood on it. Heard a crack. Close inspection showed spider crack where gravel was pressed in under my weight. Does not appear to show delamination (air gap).

3) 1/4" screw driver test. Tried to puncture test piece with a 1/4" screw driver (the big one). Took about 7 tries before I swung it hard enough to make a puncture. The first 6 tries left small "star" (like a stone on your windshield) impact mark.

4) General pounding: Slammed the test piece against the work bench, floor, and on the corner on work bench. Worst damage was small star impact marks (like above) from the corner of the work bench.

Single layer 6 oz test:

1) high pressure leaning: Makes a slight depression. Can hardly see it, but I could feel the foam give under my pressure.

2) Standing: It showed compresson marks from standing on it.

3) Screwdriver puncture: Took two tries to puncture (but I already punctured the biax, so I may have swung hard to start). It seem to puncture much, much easier than the biax.

4) general punding: General pounding shows that the 6oz does not protect the foam like the biax. Don't use for a tool box made from foam! (LOL!) Or an anchor locker! But should handle having large fish tossed into a live well with no problem. Especially if you use two layers. The problem of the single layer 6oz is it does not disipate the pressure over a large area like the biax does. So dents and delamination occure when pounded.

Details at 11:00

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

Here is the biax test, and further behind it is the 6oz. Hard to see the 6oz because it turns so clear when wet out. The little dots behind the glass are puncture holes made so the resin will sink in and hopefully get a better grip on the foam.

As it turns out, when I finally got around to completely smashing the test piece, the grip holes were filled between 1/4 to 3/8" deep. I stuck a screwdriver under the glass from the edge and tried to pry the whole thing off. It did start, but was very hard to delaminate. The foam was ripping off in chunks stuck to the epoxy.

I'm happy.

 

[jonesg]

Re: Project "1600 Capri Hard Top" has begun!

The only problem I see is the top may not be as removeable as using lighter building techniques simply due to total weight.

Add heavy glass and frames , paint , lights etc and it might be more than you want to lift.

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

The only problem I see is the top may not be as removeable as using lighter building techniques simply due to total weight.

Add heavy glass and frames , paint , lights etc and it might be more than you want to lift.

Yeah, I think you are right. Even if it gets a bit heavy, we will just use two or three people to take it on and off. I just made it removeable because I could, I really don't plan to remove it unless I need to put the boat in the garage, and then my wife has suggested getting one of those portable garages with 10' headroom.

I had planned on doing the whole top inside and out with the 1807 biax, but after seeing how tough the stuff really is, I am only putting it on the outside and the inside will be done in a single 6oz glass, except for the windshield area, that will get biax inside too for strength and rigidity. That should save about 20 to 25 lbs alone. And one layer of 6oz is good enough to protect the foam on the interior and give a good surface to paint.

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

One question for the epoxy experts here: How come on the test piece (see above) the epoxy cured hard and tack free on the 1708 biax, but cured hard and tacky on the 6oz. The epoxy was mixed all at once, applied at once and was mixed very well. I noticed that the epoxy that hardened in the cup was not tacky. The biax got hot, the 6oz didn't and the cup got so hot it melted. Does heat have something to do with fully curing the epoxy? Will the 6oz eventually cure and lose the tackyness?

 

[jonesg]

Re: Project "1600 Capri Hard Top" has begun!

Yeh temp has everything to do with resin going off, hit the 6 oz with a heat gun and it'll trip off pronto.
A deep batch of resin left in a cup can catch fire.

I prefer to mix in a shallower , rather than deeper, container and get it out of the container onto the cloth asap when doing larger areas.
You can slow epoxy down a bit just by varying the catalyst a bit too.
I like to thin it out a bit with alcohol, makes for easier brush application and slows it down. The alcohol vents off in 30 minutes or so.

Another factor is whether the cloth is treated with volon, that makes wetting the cloth out easier but adds to cost.

I like to start (flat areas) by dry brushing the cloth onto the intended surface, it imparts a static charge that makes it cling, then drizzle resin on and brush out from the center , squeegee if needed.
Just find a way that works for you.

I do business locally with a place that mfgers co-polymers for nasa, "shuttle glue" you could call it. They have an acrylic polymer thats neat, you mix a powdered catalyst with the liquid resin and it will stick to any other resin you apply it to.

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

Yeh temp has everything to do with resin going off, hit the 6 oz with a heat gun and it'll trip off pronto.
A deep batch of resin left in a cup can catch fire.
....
.

I realize now that the thicker layer of epoxy kicks fast and hardens with no anime blush, but thinner layers, like on the 6oz, take longer to harden and get anime. Well tonight I noticed that the 6oz test still was sticky, so I washed it and BINGO, it is clean and hard. It was the greasy anime I was feeling.


Here are the latest photos of the top progress:

Before glassing, spent two hours working the roof to remove the dip and sanded the heck out of it. Now just two small ridges need to be filled. Pic is top with second coat of epoxy. That is one piece of 1708 biax 10ft x 50 inches. . Man, those vertical surfaces sure were hard to wet out fully. Even the top flat surface was hard to do. That 1708 biax is thick, tight weave and hard to work with compared to regular weaves. But it sure made the top rigid. I pulled down hard on the center rear of the top, and the 2x4 its resting on bent, not the top. W O W !

View of where the roof meets the side. This will take a little fairing...

 

[redfury]

Re: Project "1600 Capri Hard Top" has begun!

Looks good! It's finally starting to look like a project in progress instead of a mock up.

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

Looks good! It's finally starting to look like a project in progress instead of a mock up.

Yeah, my wife said "I never thought you would get to this part..." Thanks honey...

 

[jonesg]

Re: Project "1600 Capri Hard Top" has begun!

I like epoxy but it doesn't seem to wet out as easy as poly, have you tried adding just a bit of denatured alcohol, that helps the resin to soak through the cloth easily , once you have it wetted with the thinned epoxy then brush regular epoxy on, the epoxy already in the cloth will act like a capillary bridge or is it ionic bridge?..and draw it through. After a while the alcohol vents off and the epoxy cures as normal.
Acetone works better but you're doing this directly on foam.

basically mix up one batch and thin 1/3rd of it, it will go on a lot quicker, then come back with the unthinned resin.

I use a gadget for putting lots of holes in foam in no time, called a docker.
http://www.webstaurantstore.com/dough-docker-heavy-duty/124DD5704.html

I'm a baker by trade.

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

I like epoxy but it doesn't seem to wet out as easy as poly, have you tried adding just a bit of denatured alcohol, that helps the resin to soak through the cloth easily , once you have it wetted with the thinned epoxy then brush regular epoxy on, the epoxy already in the cloth will act like a capillary bridge or is it ionic bridge?..and draw it through. After a while the alcohol vents off and the epoxy cures as normal.
Acetone works better but you're doing this directly on foam.

basically mix up one batch and thin 1/3rd of it, it will go on a lot quicker, then come back with the unthinned resin.

I use a gadget for putting lots of holes in foam in no time, called a docker.
http://www.webstaurantstore.com/dough-docker-heavy-duty/124DD5704.html

I'm a baker by trade.

Thanks for the alcohol tip. I have a can of denatured alcohol for cleaning up, I'll try thinning some epoxy with it.

And that dough hocky looks like it would do the job in no time! I just drew a few lines and started jabbing away with a sharp pencil... it was quick and easier than making a block of nails.

 

[oops!]

Re: Project "1600 Capri Hard Top" has begun!

heh heh heh....was just catching up with this one......about the 1708 tests.....

thats really tough stuff...im doing some grinding of it right now....i ground down a section so it is paper thin.....its still super strong.

my hull bottom has approx 10 layers of that stuff....and yes....my barge is heavy !

your proj is looking great bud

cheers
oops

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

heh heh heh....was just catching up with this one......about the 1708 tests.....

thats really tough stuff...im doing some grinding of it right now....i ground down a section so it is paper thin.....its still super strong.

my hull bottom has approx 10 layers of that stuff....and yes....my barge is heavy !

your proj is looking great bud

cheers
oops

Wow! 10 layers? Watcha makin? An ice breaker? that must be an inch or so thick.

PS I read your thread when I need some inspiration and motivation. Then the innovation and perspiration starts....

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

Back from vacation and still have a few days before I have to go to work. So I'm working on the hardtop.

One thing I realized quickly is that it is much easier to work with smaller pieces of glass fabric than large pieces. This is because a lot of effort is needed to wrap the glass around openings and lots of paint brush work is required. This eats up time fast, and the resin starts to harden. So smaller pieces are the trick, especially when not working on large flat areas.

Did almost the entire front windshield area, just have a few pieces to fit in, and various reinforcement pieces from behind.

Finally getting the hang of it all, and its coming out better with every mix of epoxy. A lot different than working with polyester.

The anime blush with this resin is nothing more than a clear sticky layer on the top that will wash off with the garden hose. I used some dish detergent and a soft scrub brush just to be sure its all off, but after drying in the sun, the glass was dry and tack-free.

Here are some photos.

Here the front of the roof is done, coming 1/3 down the windshield, and the lower portion of the windshield is done also. The reason I didn't fill the center is I didn't want to stop to wash off the anime blush. Just have to connect the two areas. I have pounded on this top with my fists, and it is solid as can be.

And I didn't get to use all the cabosil mix before it starte to set up. Here is a baseball size glob hard as a rock.

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

This morning I got under the top and picked it up myself. I am surprised at how light it still is with 3/4 of the heavy glass work done. Walked it outside, and scrubbed yesterdays work clean with dish detergent and water, then hosed clean. While it dried, I mixed up some bug killer and sprayed the tent catipillars in the trees, and hornet nests around the hose spigots. Gotta do double duty.

It is becoming obvious to me that cabosil used to thicken resin is an art form. The problem is two fold: one, mixing a powder that is micro sized particals into a heavy syrup is hard. The cabosil tends to just float on the surface. Mixing is difficult by hand. Second, even if you mix it thick enough to be like putty, when it finally starts to harden, and heat builds up, it instantly starts to get thin and runny. So continual re-shaping of any fill area is needed until hardened. Major pain, especially when you are getting tired.

I used cabosil to make a peanut butter like paste to fill in corners using a plastic spoon to make the radius. That turned in to such an effort, and dripping epoxy, smearing , etc that I decided to skip that step for now. But I am working on vertical and over head surfaces, and that makes everything 300% harder to deal with. Making a bead and forming to a radius where the boat floor meets the hull would be much easier because its a flat, horizontal surface.

Today I want to finish the vertical windshield posts, some areas around the side windows, and the rib behind the V in the middle of the windshield. That will all be done in smaller pieces, and should only take about 6 hours at the rate I work.

More pics to follow later today.

 

[drewpster]

Re: Project "1600 Capri Hard Top" has begun!

Have you tried adding some wood flour or micro-balloons to help your filleting? I used micro balloons and came up with a consistency just like peanut butter using medium speed hardener. No runs, packed well shaped well. You might try it.

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

Have you tried adding some wood flour or micro-balloons to help your filleting? I used micro balloons and came up with a consistency just like peanut butter using medium speed hardener. No runs, packed well shaped well. You might try it.

I tried a 50/50 mix that sagged when it "kicked off", then a 25/75 mix that was so thick it was hard to stir. It still sagged when it "kicked off".

Problem might be just that I am working overhead and not with gravity.

 

[jonesg]

Re: Project "1600 Capri Hard Top" has begun!

Put some cardboard down and flip it over.! Why work upside down when you made it removeable.

Once you get the ratio of silica to use , just mix it into the resin first before catalysing.
Extra mixing time = +heat.

I've also put leftover epoxy in the freezer to slow it down.
Mix some, take what you need and chill the extra, only works for a few extra minutes w/ silica. ...much longer with straight epoxy tho.

How many times did you glue something then just as the epoxy goes off you remember the 3 other things that needed gluing?
Its a decent time saver for non critical applications.

 

[Mark42]

Re: Project "1600 Capri Hard Top" has begun!

I'll have to try the freezer trick. Yesterday I did flip the top over to start working on the inside. I added a rib down the center of the front windows for strength.

It is so much easier working that way. Will continue working upsidedown while working on the interior.

I am continually amazed at how strong the 1708 glass on foam is. Incredible!!!!