The C-Brats Forum Index
HomeForumsMy TopicsCalendarEvent SignupsMemberlistOur C-DorysThe Brat MapPhotos

 Balsa Core Issues 
I drilled them out oversized so that they could be filled with epoxy putty for a proper deck mounting.  The swarf looks good, but it was soaking wet.
I drilled them out oversized so that they could be filled with epoxy putty for a proper deck mounting. The swarf looks good, but it was soaking wet.
Viewed: 647 times.

Here was one of the leaks.  The cleat was set in silicon bath tub caulk, which can work okay if there is no pressure placed on the fitting.  Wait a minute.  Oh yeah, it's a cleat.  This will have to be bored out and filled with epoxy.  I found that a
Here was one of the leaks. The cleat was set in silicon bath tub caulk, which can work okay if there is no pressure placed on the fitting. Wait a minute. Oh yeah, it's a cleat. This will have to be bored out and filled with epoxy. I found that a "file card brush" was aggressive enough to remove the caulk and not damage the deck.
Viewed: 614 times.

Here's the deck with most of the hardware removed.  Even if the holes were okay (which it was on the anchor roller), I'm going to wait months before filling them in hopes that moisture will escape from all of the openings.
Here's the deck with most of the hardware removed. Even if the holes were okay (which it was on the anchor roller), I'm going to wait months before filling them in hopes that moisture will escape from all of the openings.
Viewed: 627 times.

The bow light was okay because of a big gob of caulk.
The bow light was okay because of a big gob of caulk.
Viewed: 659 times.

It still gets bored out to help dry out the boat and get a protective epoxy coating in the future.
It still gets bored out to help dry out the boat and get a protective epoxy coating in the future.
Viewed: 639 times.

I was able to get a moisture reading well away from the leaking deck fittings when I drilled a hole for the gas tank deck fill.  This shows that the balsa core is saturated throughout the boat.  The wood looks perfect, but it probably would not have lasted long at this moisture content.
I was able to get a moisture reading well away from the leaking deck fittings when I drilled a hole for the gas tank deck fill. This shows that the balsa core is saturated throughout the boat. The wood looks perfect, but it probably would not have lasted long at this moisture content.
Viewed: 638 times.

So far, every deck penetration that could be done wrong was done wrong.  I found that the little snap fittings for the bimini had been pop riveted (and many had failed because of using aluminum with stainless).  Those that had been replaced over the years also had leaked.  All have now been removed.  I only found a couple of bad spots in the balsa core, and those appeared to be discolored rather than rotten.  Again, with the balsa core moisture at full saturation, it is difficult to identify exactly what was leaking.  I didn't find anything that made me want to tear off the fiberglass laminate (from below) and examine, but then I'm also really reluctant to go there.
So far, every deck penetration that could be done wrong was done wrong. I found that the little snap fittings for the bimini had been pop riveted (and many had failed because of using aluminum with stainless). Those that had been replaced over the years also had leaked. All have now been removed. I only found a couple of bad spots in the balsa core, and those appeared to be discolored rather than rotten. Again, with the balsa core moisture at full saturation, it is difficult to identify exactly what was leaking. I didn't find anything that made me want to tear off the fiberglass laminate (from below) and examine, but then I'm also really reluctant to go there.
Viewed: 629 times.

The deck has now been opened for two months in a heated garage with a heating mat placed on the deck and heat lamps underneath.  Here, I covered the opening in the deck with plastic with a psychrometer (air moisture meter) enclosed.  Relative humidity in the garage was now down to 50%.  After 24 hours applying heat to the surrounding area, it only got to 60% RH inside of the plastic.
The deck has now been opened for two months in a heated garage with a heating mat placed on the deck and heat lamps underneath. Here, I covered the opening in the deck with plastic with a psychrometer (air moisture meter) enclosed. Relative humidity in the garage was now down to 50%. After 24 hours applying heat to the surrounding area, it only got to 60% RH inside of the plastic.
Viewed: 616 times.

I could use heat to move core moisture around, but it looked like it was basically dried out the same as any lumber in my shop, so I cut the replacement piece for a trial fit.  The outlying holes have been filled, as have the old pop rivet holes.  Those will be drilled to accept stainless steel screws to hold the seat box.
I could use heat to move core moisture around, but it looked like it was basically dried out the same as any lumber in my shop, so I cut the replacement piece for a trial fit. The outlying holes have been filled, as have the old pop rivet holes. Those will be drilled to accept stainless steel screws to hold the seat box.
Viewed: 635 times.

I masked off the surrounding area and coated the repair area with penetrating epoxy.
I masked off the surrounding area and coated the repair area with penetrating epoxy.
Viewed: 594 times.

The area was covered with a thin layer of epoxy and wood dust, the balsa set in place and covered with masonite pieces and weighted down to cure.  Not shown is that I jacked this side of the boat up off of the trailer bunk (which runs right under the repair area).  I didn't want the weight of the boat to possibly deform the hull while I did the repair.
The area was covered with a thin layer of epoxy and wood dust, the balsa set in place and covered with masonite pieces and weighted down to cure. Not shown is that I jacked this side of the boat up off of the trailer bunk (which runs right under the repair area). I didn't want the weight of the boat to possibly deform the hull while I did the repair.
Viewed: 602 times.

I used heat lamps under the raised part of the front deck.  They were moved about every 15 minutes.  The idea was to
I used heat lamps under the raised part of the front deck. They were moved about every 15 minutes. The idea was to "pump" air in and out of the balsa core by cycling between warm (hot) and cold. This was also done for two months. My electricity bill was 4 times higher for these two months than it was for the same period last year. The material costs for the repair work was about $200. The increased heating bill was twice that. That is my yellow silicon "frosting" spatula in the upper right. Highly recommended because hardened epoxy can be removed by simply flexing it.
Viewed: 661 times.

To get epoxy putty into the thin core area around the hatch, I used a home made grout bag.  I bought cake decorating tips (and the silicon frosting spreader shown in the prior picture) and loaded the baggy up with epoxy putty.  If you get the putty too stiff, it will blow out the bag.  Too thin and it will not stay in the slot.  After filling an area, I used tape to keep the putty in place.
To get epoxy putty into the thin core area around the hatch, I used a home made grout bag. I bought cake decorating tips (and the silicon frosting spreader shown in the prior picture) and loaded the baggy up with epoxy putty. If you get the putty too stiff, it will blow out the bag. Too thin and it will not stay in the slot. After filling an area, I used tape to keep the putty in place.
Viewed: 648 times.

The tape is being removed to show the hardened putty.  The putty goes in over 1 inch, allowing the mounting screws for the hatch to now go into the epoxy rather than the balsa core.  The heat lamps are still being used on the little side deck where the pulpit and cleats have allowed water in.  I had to drill additional holes from underneath to let the moisture out and monitor the drying process.
The tape is being removed to show the hardened putty. The putty goes in over 1 inch, allowing the mounting screws for the hatch to now go into the epoxy rather than the balsa core. The heat lamps are still being used on the little side deck where the pulpit and cleats have allowed water in. I had to drill additional holes from underneath to let the moisture out and monitor the drying process.
Viewed: 657 times.

The front hatch was reinstalled
The front hatch was reinstalled "PNW style" (i.e., backwards). I'm not concerned about getting cool air inside on the two days a year that it is hot in Seattle. I'm more concerned about keeping drizzle out 320 days of the year. Plus, I can use a squirt bottle to clean salt spray off the wind shield. All of the forward deck hardware is now reinstalled. In the background on the shelving above the bow pulpit are the EPS floatation pieces that are behind the cockpit covers in the 16 Cruiser. Most will be reinstalled.
Viewed: 630 times.

Here is the new core with two layers of glass cloth and Peel Ply release fabric over the whole repair.  Peel Ply allowed me to fair out the resin.  The surrounding exploratory holes and the bored out old pop rivet holes have all been filled with epoxy putty.  The mess is cleaned up.
Here is the new core with two layers of glass cloth and Peel Ply release fabric over the whole repair. Peel Ply allowed me to fair out the resin. The surrounding exploratory holes and the bored out old pop rivet holes have all been filled with epoxy putty. The mess is cleaned up.
Viewed: 654 times.

Here is a close up of the edge.  I removed some of the warp (or weft) from the edges to make the layers lie down and fair in better.  The horizontal light line under the fiberglass is lightly colored epoxy putty at the edge of the repair.  The difference in colors made it easy to see where to place the fabric layers.
Here is a close up of the edge. I removed some of the warp (or weft) from the edges to make the layers lie down and fair in better. The horizontal light line under the fiberglass is lightly colored epoxy putty at the edge of the repair. The difference in colors made it easy to see where to place the fabric layers.
Viewed: 669 times.

Here is the other edge (new balsa to the right).  The dividing line has two layers of 6 oz. cloth, with the second layer having strands removed, then the first layer of cloth, with strands removed from its edge.  All was faired by the release cloth.  No sanding and the repair will be easily covered with deck texture.  The light dot in the center is a test hole that was filled with epoxy putty when I determined that the water damage didn't go out that far.
Here is the other edge (new balsa to the right). The dividing line has two layers of 6 oz. cloth, with the second layer having strands removed, then the first layer of cloth, with strands removed from its edge. All was faired by the release cloth. No sanding and the repair will be easily covered with deck texture. The light dot in the center is a test hole that was filled with epoxy putty when I determined that the water damage didn't go out that far.
Viewed: 1072 times.

Powered by Gallery v1



Page generation time: 1711725454.97s (PHP: 100% - SQL: 0%) - SQL queries: 9 - GZIP disabled - Debug on