3M5200 vs PC-11 Epoxy for permanent fix - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Repairs/Mods
  3M5200 vs PC-11 Epoxy for permanent fix

search | FAQ | profile | register | author help

Author Topic:   3M5200 vs PC-11 Epoxy for permanent fix

Smithsm posted 06-18-2008 10:16 AM ET (US)
I have the need to reseal what appears to be old transducer screw holes in my transom that were originally sealed but have hair line cracks around them and are not now perfectly water tight.
I discovered them by observing a very small "leak" from the boat while it was on it's trailer. The boat appeared to have a drop of "oil" colored liquid come through the ablative bottom paint and form a single drop.
After using a dremel with a small wire brush to remove all old bottome paint I uncovered two holes that had been plugged up, but apparently the plugs were not working 100.
My plan is to drill out the old "plugs" and then reseal it with either PC-11 Marine two part epoxy or 3M5200.
this is intended to be a super permanent fix that will be covered by bottom paint.
My inclination would have been to use the pc-11 as it is super hard and intended for totally permanent marine use but 3m5200 seems populare as well - but it takes a long time to set up and that might interfere with acheiving a perferct adhesion.
here is the pc-11 site http://www.pcepoxy.com/pastepoxies/pastepc11.asp
they probobly both would work - but I am leaning to the pc-11 because it is a two part epoxy. any advice ?
Smithsm posted 06-18-2008 10:40 AM ET (US)
I think I just answered my question.
I found the technical data sheets for both products and plan to use the pc-11 - unless someone points out something I am missing.
my decision is based on three criteria.
1. shorter cure time for pc-11 decreases chance of poor adhesion caused by moisture - more of the dark stuff.
2. higher tensile strengh of pc-11 (1710 vs 705) - I hope these tests were "apples to apples"
3. higher hardness value (72 vs 68)
both products would probobly work but the faster cure time for the pc-11 gives me greater certainty of solid adhesion
Tom W Clark posted 06-18-2008 10:49 AM ET (US)
You could also use 3M 5200 FC (fast cure).
There are a couple reasons you might want to use the polyurethane caulk:
Polyurethane caulks cure by moisture so if there is some residual moisture in the holes/transom, this will not impair adhesion.
Polyurethane caulk will be easier to use coming, as it does, in a convenient tube with a fine point tip. No mixing required.
One the other hand, epoxy will be hard while on the other the caulk will remain slightly flexible. Sometimes that is good and other times that is not.
You could also use the caulk to fill and seal the hole and then top coat the surface with the epoxy to obtain a perfectly fair, hard surface to apply paint to.
You can also use polyurethane glue (Gorilla is one brand) to fill and seal the hole and then top coat with epoxy.
Smithsm posted 06-18-2008 11:09 AM ET (US)
Tom
thanks for your ideas.
if i drill out the old repair, fill the inner part with 5200 and the outer layer with pc-11 how long do you think I should wait for the 5200 to totally cure ? or do you think it even needs to totally cure before I apply the pc-11?
by the way, the pc-11 is advertised as curing under water so I think the moisture should not effect it, SO LONG AS i GET A GOOD DRY GRIP IN THE FIRST PLACE.
your ideas are always appreciated.
Tom W Clark posted 06-18-2008 11:13 AM ET (US)
All epoxies cure under water but moisturer will impair the adhesion to the surrounding surface.
3M 5200 will cure in a week or ten days. 3M 5200 FC will cure in a day or two.
Smithsm posted 06-18-2008 12:01 PM ET (US)
Tom
thanks for the clarification on the "cure vs adhere" issue with epoxy
I just found the source of the problem. After carefull removeal of the paint I started to "pick at" the four holes with a set of fine tweezers. Out came 4 nice white soft caulk type plugs - probably silicone - certainly feels soft and squishy like silicone.
I drilled out the holes to sligtly oversized and the good news is I hit solid wood.
These holes are still pretty small - and the 5200, with it's end tube tip, will probably get up and into the holes better.
Bluejay15 posted 06-18-2008 12:59 PM ET (US)
I would use Marine Tex in your situation.
Tohsgib posted 06-18-2008 01:17 PM ET (US)
In 1983 I hit a submerged rock and ripped off a piece of gel and glass on the ti of my transom. Filled ait with PC11 and it is still there today. Little harder to sand, etc but it is strong.
Tom W Clark posted 06-18-2008 01:40 PM ET (US)
Marine-Tex is an epoxy putty.
Bluejay15 posted 06-18-2008 02:38 PM ET (US)
Yep, 2 part epoxy. Works great in small cases like this very hard tensile strength of 4000 psi, but is hard to sand. I would not use something soft and flexible like 5200 in this case. Using 5200 then an outer coat of something hard seems more than what is needed. Unless water is still dripping out and you need to stop the drip before you can work.
Something I learned is to get your finger wet with water then smooth the 5200 or Marine Tex with your finger to smooth it out so you do not have to sand. And with the case of 5200 you cannot sand it smooth.
Smithsm posted 06-19-2008 04:31 PM ET (US)
What i have done so far is to use to squirt 5200 up into the holes and taped them shut to keep it from running out. I really did not think I could have fully filled the holes with a two part putty expoxy. I considered using nails to push the epoxy up the holes but in the end opted for the more pliable 5200.
after it sets up pretty good - which I believe will take days - I am going to take a good look and consider drilling out a little of the 5200 and using the two part epoxy
and I also found to use the wet finger does a great job of smoothing stuff to avoid sanding.
this location is at the bottom of my transom - so it will be eventually covered in bottom paint and not seen - so I am much less interested in finish than in strength and water tight seal

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: 3M5200 vs PC-11 Epoxy for permanent fix
Smithsm	posted 06-18-2008 10:16 AM ET (US) I have the need to reseal what appears to be old transducer screw holes in my transom that were originally sealed but have hair line cracks around them and are not now perfectly water tight. I discovered them by observing a very small "leak" from the boat while it was on it's trailer. The boat appeared to have a drop of "oil" colored liquid come through the ablative bottom paint and form a single drop. After using a dremel with a small wire brush to remove all old bottome paint I uncovered two holes that had been plugged up, but apparently the plugs were not working 100. My plan is to drill out the old "plugs" and then reseal it with either PC-11 Marine two part epoxy or 3M5200. this is intended to be a super permanent fix that will be covered by bottom paint. My inclination would have been to use the pc-11 as it is super hard and intended for totally permanent marine use but 3m5200 seems populare as well - but it takes a long time to set up and that might interfere with acheiving a perferct adhesion. here is the pc-11 site http://www.pcepoxy.com/pastepoxies/pastepc11.asp they probobly both would work - but I am leaning to the pc-11 because it is a two part epoxy. any advice ?
Smithsm	posted 06-18-2008 10:40 AM ET (US) I think I just answered my question. I found the technical data sheets for both products and plan to use the pc-11 - unless someone points out something I am missing. my decision is based on three criteria. 1. shorter cure time for pc-11 decreases chance of poor adhesion caused by moisture - more of the dark stuff. 2. higher tensile strengh of pc-11 (1710 vs 705) - I hope these tests were "apples to apples" 3. higher hardness value (72 vs 68) both products would probobly work but the faster cure time for the pc-11 gives me greater certainty of solid adhesion
Tom W Clark	posted 06-18-2008 10:49 AM ET (US) You could also use 3M 5200 FC (fast cure). There are a couple reasons you might want to use the polyurethane caulk: Polyurethane caulks cure by moisture so if there is some residual moisture in the holes/transom, this will not impair adhesion. Polyurethane caulk will be easier to use coming, as it does, in a convenient tube with a fine point tip. No mixing required. One the other hand, epoxy will be hard while on the other the caulk will remain slightly flexible. Sometimes that is good and other times that is not. You could also use the caulk to fill and seal the hole and then top coat the surface with the epoxy to obtain a perfectly fair, hard surface to apply paint to. You can also use polyurethane glue (Gorilla is one brand) to fill and seal the hole and then top coat with epoxy.
Smithsm	posted 06-18-2008 11:09 AM ET (US) Tom thanks for your ideas. if i drill out the old repair, fill the inner part with 5200 and the outer layer with pc-11 how long do you think I should wait for the 5200 to totally cure ? or do you think it even needs to totally cure before I apply the pc-11? by the way, the pc-11 is advertised as curing under water so I think the moisture should not effect it, SO LONG AS i GET A GOOD DRY GRIP IN THE FIRST PLACE. your ideas are always appreciated.
Tom W Clark	posted 06-18-2008 11:13 AM ET (US) All epoxies cure under water but moisturer will impair the adhesion to the surrounding surface. 3M 5200 will cure in a week or ten days. 3M 5200 FC will cure in a day or two.
Smithsm	posted 06-18-2008 12:01 PM ET (US) Tom thanks for the clarification on the "cure vs adhere" issue with epoxy I just found the source of the problem. After carefull removeal of the paint I started to "pick at" the four holes with a set of fine tweezers. Out came 4 nice white soft caulk type plugs - probably silicone - certainly feels soft and squishy like silicone. I drilled out the holes to sligtly oversized and the good news is I hit solid wood. These holes are still pretty small - and the 5200, with it's end tube tip, will probably get up and into the holes better.
Bluejay15	posted 06-18-2008 12:59 PM ET (US) I would use Marine Tex in your situation.
Tohsgib	posted 06-18-2008 01:17 PM ET (US) In 1983 I hit a submerged rock and ripped off a piece of gel and glass on the ti of my transom. Filled ait with PC11 and it is still there today. Little harder to sand, etc but it is strong.
Tom W Clark	posted 06-18-2008 01:40 PM ET (US) Marine-Tex is an epoxy putty.
Bluejay15	posted 06-18-2008 02:38 PM ET (US) Yep, 2 part epoxy. Works great in small cases like this very hard tensile strength of 4000 psi, but is hard to sand. I would not use something soft and flexible like 5200 in this case. Using 5200 then an outer coat of something hard seems more than what is needed. Unless water is still dripping out and you need to stop the drip before you can work. Something I learned is to get your finger wet with water then smooth the 5200 or Marine Tex with your finger to smooth it out so you do not have to sand. And with the case of 5200 you cannot sand it smooth.
Smithsm	posted 06-19-2008 04:31 PM ET (US) What i have done so far is to use to squirt 5200 up into the holes and taped them shut to keep it from running out. I really did not think I could have fully filled the holes with a two part putty expoxy. I considered using nails to push the epoxy up the holes but in the end opted for the more pliable 5200. after it sets up pretty good - which I believe will take days - I am going to take a good look and consider drilling out a little of the 5200 and using the two part epoxy and I also found to use the wet finger does a great job of smoothing stuff to avoid sanding. this location is at the bottom of my transom - so it will be eventually covered in bottom paint and not seen - so I am much less interested in finish than in strength and water tight seal