Please, What do y'all think of leaving the drilling dust in the crack prep when placing the Plexiguss (sp??) filler so that it acts as a matrix to strengthen the repair? Any other repair suggestions/tips? Many Thanx. Fair Winds..... MRF
H170 Crack Repair
- Thread starter Marie T. Murphy
- Start date
NO. Make sure you drill a 1/8 inch hole thru the white skin about 3/16 inch thick at each end of the crack to keep it from spreading.
Dave, Thanx for the timely reply. I've read your other posts.........You're not so crazy, afterall. Fair Winds... MRF
Everyone, esp. CD, PLZ, 1. Do hairline cracks need to be "opened " to use Plexus? 2. What if there's already a separation between edges? 3. Do edges need to be roughened prior to seal? 4. Should I use Acetone to soften edges? 5. How/Why does an hole-prep at end of a crack prevent farther cracking ? Does another sealer work on ACBS, ie: 3M 5200, Loctite, etc. ? Much Thanx, MRF
This would be the place to start for the acp hull repairs.
https://hunter.sailboatowners.com/resources/index.php
Select 146 or 170 or 216 models.
Some realy good downloads and ideas.
If you have space in the cracks, you should fill the space with some fiberglass, as well as the epoxy. If you don't have enough room for glass cloth, then I would use milled fibers.
Feathering out the edges prior to adding epoxy will give the epoxy a much wider surface to bond to & make a stronger joint.
Stop-crack drilling is a process that had been used in aircraft maintenance for many years. The crack concentrates force on a very small point & this keeps the crack moving. Drilling the hole spreads the stress evenly over a larger area & prevents it from spreading.
I have used 5200 to bond the skin to the foam when it delaminates in small areas, but this practice is not officially sanctioned & some people recommend against it. 5200 is not strong enough to close up a crack in the skin. It may be able to waterproof the crack, but it will not add structural strength. If you are looking to do more than just keep the water out, then you need stronger material. Plexus & Devcon are the two materials that are officially sanctioned. I have also had some luck with West System Epoxy. Details of my motor mount repair on a 170 can be found
Here -
https://hunter.sailboatowners.com/mods.php?task=article&mid=11&aid=100114&mn=170
& Here -
https://hunter.sailboatowners.com/mods.php?task=article&mid=11&aid=100115&mn=170
Feathering out the edges prior to adding epoxy will give the epoxy a much wider surface to bond to & make a stronger joint.
Stop-crack drilling is a process that had been used in aircraft maintenance for many years. The crack concentrates force on a very small point & this keeps the crack moving. Drilling the hole spreads the stress evenly over a larger area & prevents it from spreading.
I have used 5200 to bond the skin to the foam when it delaminates in small areas, but this practice is not officially sanctioned & some people recommend against it. 5200 is not strong enough to close up a crack in the skin. It may be able to waterproof the crack, but it will not add structural strength. If you are looking to do more than just keep the water out, then you need stronger material. Plexus & Devcon are the two materials that are officially sanctioned. I have also had some luck with West System Epoxy. Details of my motor mount repair on a 170 can be found
Here -
https://hunter.sailboatowners.com/mods.php?task=article&mid=11&aid=100114&mn=170
& Here -
https://hunter.sailboatowners.com/mods.php?task=article&mid=11&aid=100115&mn=170