Re: Stus-List C 29 Mk II Bulkhead Repair
>...heat generated by the epoxy, it kicked off like a chain reaction and >produced a very hot, softball sized but mostly air filled ball above the hole. AKA a exothermic reaction. The worst exothermic reaction I was involved with was back in the 70's when I incorrectly set a warming oven to 250F instead of 100F. I had two gallons of a two part polyurethane potting compound turn into a smoken' basketball size fire hazard. I ran it into the parking lot and dumped into some gravel. After it cooled we painted it up a little and named it. To avoid that type of exothermic reaction when mixing large (250 ml typical) batches of West Systems epoxy I have used several techniques. If it is cool outside (<60F) I use their 205 hardener. Don't add your body heat to the mixing container by holding it tightly in your hand. To add fillers, mix the resin/hardener quickly then start adding the fillers. The fillers absorb some of the chemical reaction's heat. Glass fibers or milled glass (powder) absorb more than microballons. If it is warmer to hot in the work space I used West Systems 206 hardener which is formulated for longer pot life in warm weather. In hot conditions with larger batches I have resorted to cooling the resin and hardener containers in ice water prior to mixing. When spreading / poring the mixed epoxy, quickly get some of the mixture out of the middle of the container and onto some part of the repair area that will absorb the heat. This is to help avoid the "smoken' hot ball" of epoxy. A wider / larger mixing container is also helpful to stay below the exothermic start point. If you are poring to fill a large void, poring in stages or adding some layers of glass cloth or mat to break up the large mass of resin is a good technique. The glass will absorb some heat and help prevent shrinkage and cracking. To date, we have used approx. 6 gallons of West Systems 105 resin and a mix of the equivalent 205 or 206 hardener on Calypso's deck rebuild. the typical batch is 2 to 3 "pumps" of the metering pumps. The biggest batches were up in the 10 to 12 pumps. For the big batches we had all the cloth laid out and ready to have resin poured on. We quickly got the resin out of the mixing container to avoid the exothermic reaction. With 3 to 4 layers of cloth and all that resin the heat could be felt on the skin a close to a foot away. Some of the fillers we use are: milled glass powder glass fibers / strands (approx. 1"long) West 405, 407, 410 branded fillers CaboSil (flamed silica) as an anti-slumping agent Most of our filler mixes get to the "peanut butter" thickness. For pouring into a void we go lighter on the fillers and work it to a "honey" consistency. We have used syringes to push epoxy into tight places. We have used vacuum bagging supplies and techniques to remove air and reduce the number of voids. If you pour resin into a hole it will likely "bubble" until it cures. We have sat around popping bubbles and re-filling. We have tried using a vacuum chamber to reduce bubbles from mixing. After +-300 holes filled we now just accept that some holes/voids will bubble enough to require a two step process. Martin Calypso 1971 C 43 Seattle From: CnC-List [cnc-list-boun...@cnc-list.com] on behalf of Charlie Nelson via CnC-List [cnc-list@cnc-list.com] Sent: Wednesday, April 13, 2016 2:56 PM To: cnc-list@cnc-list.com Cc: cenel...@aol.com Subject: Re: Stus-List C 29 Mk II Bulkhead Repair Be careful that whatever you do with the epoxy including adding fillers, etc. that what you are using it on, in or about has sufficient area to absorb the heat produced as the epoxy 'kicks off'. I build a wooden sailing dinghy using the 'stitch and glue (epoxy) and got pretty good with the stuff--so I thought! When I began an epoxy plus filler repair on a 1.5" x 4" x 1.5" hole in my deck, I learned quickly and fortunately without a fire, that one cannot fill such a whole in 'one go'! Without enough surface to absorb the heat generated by the epoxy, it kicked off like a chain reaction and produced a very hot, softball sized but mostly air filled ball above the hole. Had this repair been done similarly in a place where I could not easily reach it, there likely would have been a fire! Charlie Nelson Water Phantom cenel...@aol.com ___ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
Re: Stus-List C 29 Mk II Bulkhead Repair
Be careful that whatever you do with the epoxy including adding fillers, etc. that what you are using it on, in or about has sufficient area to absorb the heat produced as the epoxy 'kicks off'. I build a wooden sailing dinghy using the 'stitch and glue (epoxy) and got pretty good with the stuff--so I thought! When I began an epoxy plus filler repair on a 1.5" x 4" x 1.5" hole in my deck, I learned quickly and fortunately without a fire, that one cannot fill such a whole in 'one go'! Without enough surface to absorb the heat generated by the epoxy, it kicked off like a chain reaction and produced a very hot, softball sized but mostly air filled ball above the hole. Had this repair been done similarly in a place where I could not easily reach it, there likely would have been a fire! Charlie Nelson Water Phantom cenel...@aol.com ___ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
Re: Stus-List C 29 Mk II Bulkhead Repair
Fortunately, I have a lot of friends including a guy familiar with the West
System. He has done some extensive work on damaged boats. I have tempted him
with a few beers to look at the boat. Although I have worked on boats as a
hobby for about 65 years I never got involved in doing any repairs with epoxy.
Right now I am picking as many brains as I can to gain a little knowledge.
Frank
On Wednesday, April 13, 2016 2:17 PM, Martin DeYoung via CnC-List
<cnc-list@cnc-list.com> wrote:
#yiv4003843273 P {MARGIN-BOTTOM:0px;MARGIN-TOP:0px;}We repaired a similar
bulkhead issue on Calypso by cutting out the damaged section. The section was
approx. 12" x 18". We replaced the bulkhead section with similar grade plywood
bonded in place with epoxy then adding glass cloth and epoxy over the seams.
We replaced the failed tabbing with new. If you have a very small area
immediately next to the tabbing a less invasive repair might be possible
following your Plan A. If you have a oscillating tool (Feinmaster etc.)
working in confined spaces is easier. The plunge cut blades allow for some
"micro" surgery. Have you visited the West System's web site? They have some
excellent boat repair guides that highlight use of their epoxy products. For a
pour in place repair adding some chopped glass fibers or similar strength
building filler will reduce the epoxy fill's chances of cracking if it flexes.
MartinCalypso1971 C 43SeattleFrom: CnC-List [cnc-list-boun...@cnc-list.com]
on behalf of Eugene Fodor via CnC-List [cnc-list@cnc-list.com]
Sent: Wednesday, April 13, 2016 10:57 AM
To: cnc-list@cnc-list.com
Cc: Eugene Fodor
Subject: Stus-List C 29 Mk II Bulkhead Repair
The base of the bulkhead on the C 29 Mk II I'm in escrow on has some soft
wood and the tabbing has separated. This is the bulkhead just aft of the head
that the table is mounted on. Does anyone have experience with repairing this
and any recommendations. My plan is to sand/grind out the existing wood and
build it up with epoxy and then redo the tabbing. Any recommendations or links
on info for similiar repairs would be much appreciated.
Thank in advance,
Gene
___
This list is supported by the generous donations of our members. If you like
what we do, please help us pay for our costs by donating. All Contributions are
greatly appreciated!
___
This list is supported by the generous donations of our members. If you like
what we do, please help us pay for our costs by donating. All Contributions are
greatly appreciated!
Re: Stus-List C 29 Mk II Bulkhead Repair
We repaired a similar bulkhead issue on Calypso by cutting out the damaged section. The section was approx. 12" x 18". We replaced the bulkhead section with similar grade plywood bonded in place with epoxy then adding glass cloth and epoxy over the seams. We replaced the failed tabbing with new. If you have a very small area immediately next to the tabbing a less invasive repair might be possible following your Plan A. If you have a oscillating tool (Feinmaster etc.) working in confined spaces is easier. The plunge cut blades allow for some "micro" surgery. Have you visited the West System's web site? They have some excellent boat repair guides that highlight use of their epoxy products. For a pour in place repair adding some chopped glass fibers or similar strength building filler will reduce the epoxy fill's chances of cracking if it flexes. Martin Calypso 1971 C 43 Seattle From: CnC-List [cnc-list-boun...@cnc-list.com] on behalf of Eugene Fodor via CnC-List [cnc-list@cnc-list.com] Sent: Wednesday, April 13, 2016 10:57 AM To: cnc-list@cnc-list.com Cc: Eugene Fodor Subject: Stus-List C 29 Mk II Bulkhead Repair The base of the bulkhead on the C 29 Mk II I'm in escrow on has some soft wood and the tabbing has separated. This is the bulkhead just aft of the head that the table is mounted on. Does anyone have experience with repairing this and any recommendations. My plan is to sand/grind out the existing wood and build it up with epoxy and then redo the tabbing. Any recommendations or links on info for similiar repairs would be much appreciated. Thank in advance, Gene ___ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
Stus-List C 29 Mk II Bulkhead Repair
The base of the bulkhead on the C 29 Mk II I'm in escrow on has some soft wood and the tabbing has separated. This is the bulkhead just aft of the head that the table is mounted on. Does anyone have experience with repairing this and any recommendations. My plan is to sand/grind out the existing wood and build it up with epoxy and then redo the tabbing. Any recommendations or links on info for similiar repairs would be much appreciated. Thank in advance, Gene ___ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
