5200 or 4200 on new Transducer??
04-08-2018, 07:26 AM
#1
Senior Member
Thread Starter
5200 or 4200 on new Transducer??
Sooo...I'm onto installing a new thru hull Transducer. After all the effort I went thru getting a 5200'd TD out of my hull you might think I'm mental reconsidering doing the exact same thing!!
So should I use 4200 or 5200? My friend just went thru the same decision tree and used 5200 (again) saying that over time a 4200 sealant might leak!
So should I use 4200 or 5200? My friend just went thru the same decision tree and used 5200 (again) saying that over time a 4200 sealant might leak!
04-08-2018, 07:57 AM
#6
5200
just installed an airmar B75M last night. Used 5200. Took me a week to build up enough courage to drill the hole thru the boat. They had one mounted on the exterior of the boat that didnt pick up at all while you were running, so i Installed a thru hull.
Good luck . I would use 5200
Good luck . I would use 5200
04-08-2018, 08:23 AM
#8
Senior Member
Originally Posted by Re-Bait
Sooo...I'm onto installing a new thru hull Transducer. After all the effort I went thru getting a 5200'd TD out of my hull you might think I'm mental reconsidering doing the exact same thing!!
So should I use 4200 or 5200? My friend just went thru the same decision tree and used 5200 (again) saying that over time a 4200 sealant might leak!
So should I use 4200 or 5200? My friend just went thru the same decision tree and used 5200 (again) saying that over time a 4200 sealant might leak!
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04-08-2018, 08:44 AM
#9
Senior Member
5200 is often too permanent for stuff like transducers.
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04-08-2018, 09:14 AM
#11
Admirals Club
5200 below water line always. Why would you risk having a failed sealant joint on a 2” hole in the bottom of your boat? You’re cutting a hole in the continuos lamination on the bottom, so using 5200 integrates the transducer back into that structure. Plus it seals and adheres to the fiberglass to prevent delamination and water intrusion into the laminate.
With the proper techniques, removing something installed with 5200 is no big deal, just need to have patience. Use copious amounts of anti-bond and steady pressure, you will hear it start to crackle, let the pressure do the work and slowly increase as needed. Never had an issue removing things with this method, just takes time and persistence lol.
With the proper techniques, removing something installed with 5200 is no big deal, just need to have patience. Use copious amounts of anti-bond and steady pressure, you will hear it start to crackle, let the pressure do the work and slowly increase as needed. Never had an issue removing things with this method, just takes time and persistence lol.
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04-08-2018, 09:37 AM
#12
Admirals Club
Originally Posted by sundancekid
5200 below water line always. Why would you risk having a failed sealant joint on a 2” hole in the bottom of your boat? You’re cutting a hole in the continuos lamination on the bottom, so using 5200 integrates the transducer back into that structure. Plus it seals and adheres to the fiberglass to prevent delamination and water intrusion into the laminate.
With the proper techniques, removing something installed with 5200 is no big deal, just need to have patience. Use copious amounts of anti-bond and steady pressure, you will hear it start to crackle, let the pressure do the work and slowly increase as needed. Never had an issue removing things with this method, just takes time and persistence lol.
With the proper techniques, removing something installed with 5200 is no big deal, just need to have patience. Use copious amounts of anti-bond and steady pressure, you will hear it start to crackle, let the pressure do the work and slowly increase as needed. Never had an issue removing things with this method, just takes time and persistence lol.
04-08-2018, 09:43 AM
#14
Originally Posted by Re-Bait
Sooo...I'm onto installing a new thru hull Transducer. After all the effort I went thru getting a 5200'd TD out of my hull you might think I'm mental reconsidering doing the exact same thing!!
So should I use 4200 or 5200? My friend just went thru the same decision tree and used 5200 (again) saying that over time a 4200 sealant might leak!
So should I use 4200 or 5200? My friend just went thru the same decision tree and used 5200 (again) saying that over time a 4200 sealant might leak!
04-08-2018, 10:09 AM
#15
Admirals Club
Good summary: Adrift at Sea » Marine Sealants in a Nutshell
I've gotten away from polyurethane sealants and moved to polysulfides now (Life Caulk....I think 3m stopped making polysulfides). And I NEVER use silcone anywhere near fiberglass (look up silcone contamination...once it gets in glass/gelcoat, you gotta grind away to ever get resin to bond).
BTW, 3m 4000UV is absolute junk. I used it on my boat, and after 10 months it was chalking so badly that if you touch it, you get white allover your hands. Ironically, the 5200 that is next to it with same exposure and age does not have this problem. I read on forums somewhere that a pissed off boater finally got in touch with a 3m engineer that admitted their formula was FUBAR. What caulk to use, now that 3M 101 is no longer available, to seal the toe-rail-to-d - Cruisers & Sailing Forums
There are four major classes of bedding compounds/sealants used on a boat.
Polyurethane-based sealants are basically adhesives with sealant properties. They are often very permanent and have very strong adhesion strength, and can be used both above and below the waterline.............. 3M 5200, a polyurethane sealant commonly found in marine chandleries, is basically for all intents and purposes a permanent adhesive and should not be used on boats for the most part. 3M 5200 has a bonding strength so high that it can often cause delamination or damage the gelcoat when you try to remove hardware bedded with it. .................
Polysulfide-based sealants are the best general purpose sealants for marine use. They are not as aggressively adhesive as polyurethane-based sealants and generally a bit more elastic and flexible. They can be used both above and below the waterline, like the polyurethane sealants, and are better than polyurethane-based sealants for hardware that has to be re-bedded more frequently. (from link above)
- Polyurethane-based sealants like 3M 4200 and 5200, SikaFlex 291, 292, 295, 296
- Polysulfide-based sealants like LifeCaulk and 3M 101
- Silicone-based sealants, like Dow 795
- Butyl Rubber Glazing tape—this is not butyl rubber caulk
Polyurethane-based sealants are basically adhesives with sealant properties. They are often very permanent and have very strong adhesion strength, and can be used both above and below the waterline.............. 3M 5200, a polyurethane sealant commonly found in marine chandleries, is basically for all intents and purposes a permanent adhesive and should not be used on boats for the most part. 3M 5200 has a bonding strength so high that it can often cause delamination or damage the gelcoat when you try to remove hardware bedded with it. .................
Polysulfide-based sealants are the best general purpose sealants for marine use. They are not as aggressively adhesive as polyurethane-based sealants and generally a bit more elastic and flexible. They can be used both above and below the waterline, like the polyurethane sealants, and are better than polyurethane-based sealants for hardware that has to be re-bedded more frequently. (from link above)
BTW, 3m 4000UV is absolute junk. I used it on my boat, and after 10 months it was chalking so badly that if you touch it, you get white allover your hands. Ironically, the 5200 that is next to it with same exposure and age does not have this problem. I read on forums somewhere that a pissed off boater finally got in touch with a 3m engineer that admitted their formula was FUBAR. What caulk to use, now that 3M 101 is no longer available, to seal the toe-rail-to-d - Cruisers & Sailing Forums
04-08-2018, 10:22 AM
#16
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Read 3M's specs and they will tell you the sealant properties of both are the same. However the adhesive properties of 5200 is greater.
5200 is for use where the mechanical holding properties of what is being installed may not be adequate by themselves. Such as joints using a screw every few inches etc. A thru hull transducer comes with adequate hardware to permenately tighten it in place, 5200 won't waterproof it any better. But it will make it much more of a headache for whoever has to service it later.
5200 is for use where the mechanical holding properties of what is being installed may not be adequate by themselves. Such as joints using a screw every few inches etc. A thru hull transducer comes with adequate hardware to permenately tighten it in place, 5200 won't waterproof it any better. But it will make it much more of a headache for whoever has to service it later.
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