Notices
The Boating Forum

5200 or 4200 on new Transducer??

Old 04-08-2018, 07:26 AM
  #1  
Senior Member
Thread Starter
 
Join Date: Oct 2006
Location: LBI NJ
Posts: 3,025
Received 964 Likes on 561 Posts
Default 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!
Old 04-08-2018, 07:31 AM
  #2  
Admirals Club Admiral's Club Member
 
Blue agave's Avatar
 
Join Date: Aug 2016
Location: West Central FL
Posts: 545
Received 165 Likes on 83 Posts
Default

May want to look into 3M 4000
Old 04-08-2018, 07:36 AM
  #3  
Admirals Club Admiral's Club Member
 
Join Date: May 2017
Location: Winter Haven FL
Posts: 1,453
Received 448 Likes on 263 Posts
Default

I'm old school on this one. 5200 below waterline, 4200 above.
Old 04-08-2018, 07:45 AM
  #4  
Junior Member
 
Join Date: Feb 2013
Posts: 11
Likes: 0
Received 1 Like on 1 Post
Default

I use 4200 for ducers
Old 04-08-2018, 07:54 AM
  #5  
Admirals Club Admiral's Club Member
 
Join Date: Sep 2014
Location: Long Island Sound, NY
Posts: 2,794
Received 775 Likes on 416 Posts
Default

4200 is more than sufficient for below the waterline. 5200 should be used for things like hull to deck joints.
Old 04-08-2018, 07:57 AM
  #6  
Senior Member
 
Join Date: Nov 2011
Posts: 133
Received 11 Likes on 5 Posts
Default 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
Old 04-08-2018, 07:57 AM
  #7  
Senior Member
 
Join Date: Nov 2010
Location: Medina/Catawba Is Ohio
Posts: 1,052
Received 120 Likes on 101 Posts
Default

Boat Life is all I ever use never had a issue used it a B175hw 3 7/8" hole
Old 04-08-2018, 08:23 AM
  #8  
Senior Member
 
Join Date: Apr 2014
Posts: 114
Likes: 0
Received 12 Likes on 6 Posts
Default

Originally Posted by Re-Bait View Post
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!
I refuse to use 5200 on anything, anywhere....I’ll let my boat sink before I do.
Likes:
Old 04-08-2018, 08:44 AM
  #9  
Senior Member
 
Join Date: Jan 2006
Location: Sunny florida
Posts: 25,354
Received 5,445 Likes on 3,479 Posts
Default

5200 is often too permanent for stuff like transducers.
Likes:
Old 04-08-2018, 09:10 AM
  #10  
Senior Member
 
Join Date: Oct 2002
Location: Dryden/Ludington, MI - Steamboat, CO
Posts: 2,051
Received 582 Likes on 350 Posts
Default

4200. No reason for 5200 unless you like to cause yourself headaches later in life
Likes:
Old 04-08-2018, 09:14 AM
  #11  
Admirals ClubCaptains Club Member Admiral's Club Member
 
Join Date: Dec 2003
Location: Fort Lauderdale, FL
Posts: 6,795
Received 558 Likes on 336 Posts
Default

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.
Likes:
Old 04-08-2018, 09:37 AM
  #12  
Admirals Club Admiral's Club Member
 
Join Date: Sep 2014
Location: Long Island Sound, NY
Posts: 2,794
Received 775 Likes on 416 Posts
Default

Originally Posted by sundancekid View Post
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.
Your not risking anything by using something other than 5200. Anything you put in your hull below the waterline should either be thru bolted or backed with a threaded nut. Its not just going to fall out because you didn't use a permanent bonding adhesive. 4200 is an adhesive and 5200 is a bonding adhesive. Its not wrong but its way overkill. Life caulk is more than enough. Ive never pulled anything out easy with 5200.
Old 04-08-2018, 09:41 AM
  #13  
Senior Member
 
Join Date: Aug 2017
Posts: 893
Received 306 Likes on 183 Posts
Default

Originally Posted by BrokeLoser View Post


I refuse to use 5200 on anything, anywhere....I’ll let my boat sink before I do.
now here’s a thinker🤪
Old 04-08-2018, 09:43 AM
  #14  
Senior Member
 
Join Date: Aug 2017
Posts: 893
Received 306 Likes on 183 Posts
Default

Originally Posted by Re-Bait View Post
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!
5200 will never let you down.
Old 04-08-2018, 10:09 AM
  #15  
Admirals Club Admiral's Club Member
 
Join Date: Apr 2016
Posts: 573
Likes: 0
Received 353 Likes on 235 Posts
Default

Good summary: Adrift at Sea » Marine Sealants in a Nutshell

There are four major classes of bedding compounds/sealants used on a boat.
  • 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)
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
Old 04-08-2018, 10:22 AM
  #16  
Senior Member
 
Join Date: Dec 2017
Location: North of Cuber, South of Jawga
Posts: 1,044
Received 703 Likes on 375 Posts
Default

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.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.