# Seam sealer: dynatron vs urethane? **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [January 9, 2025, 9:56pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643 "2025-01-09T21:56:51Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [January 9, 2025, 9:56pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/1 "2025-01-09T21:56:51Z")
From the 3m versions, the urethan is about 2x the price of the dynatron. What are the compromises? ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [January 9, 2025, 10:33pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/2 "2025-01-09T22:33:19Z")
I don’t have experience using the products. Just saying a product is urethane isn’t adequate. What specific 3M urethane product are you comparing the the 3M 550 caulk? The SDS shows enough information about the 550 caulk to see that it is a modified synthetic rubber. Some of the additives, like quartz and silica, would improve wear resistance. It looks like a quality product from a very professional organization. It almost certainly would work for whatever it is you want to use it for as long as it is filling a seam. Generally urethane parts last longer than synthetic rubber parts. Bushings are an example. The specific polymers used for filling seams and bushings are different, but the basic materials are the same in any application and are modified to work best in the specific application they are intended for. Doing some body work? What is it? Maybe someone else on the board has bodywork experience and can comment on these materials in repair work. We still need to know the specific urethan though. Edit: it looks like the 570 polymer is the Dynatron that is synthetic rubber. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [January 9, 2025, 10:46pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/3 "2025-01-09T22:46:50Z")
> [@jtsanders](#): > > What specific 3M urethane product 3m product 08368 is the one I’m thinking of using. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [January 9, 2025, 10:47pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/4 "2025-01-09T22:47:35Z")
What is it for? No idea what these products do. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [January 9, 2025, 10:52pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/5 "2025-01-09T22:52:37Z")
> [@texases](#): > > What is it for? No idea what these products do. I’m new to these products, but my understanding is they are used by body shops to seal the interface between separate body panels so water cannot penetrate. My truck has a couple of spots like that where rust is trying to form. ---
**Author:** ![weekend-warrior](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/weekend-warrior/32/26122_2.png) [@weekend-warrior](https://community.cartalk.com/u/weekend-warrior)\ **Post date:** [January 9, 2025, 10:53pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/6 "2025-01-09T22:53:40Z")
[3m-urethane-seam-sealer-tds-08362-08365-08367-08368.pdf](https://multimedia.3m.com/mws/media/1004141O/3m-urethane-seam-sealer-tds-08362-08365-08367-08368.pdf) ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [January 10, 2025, 2:40am UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/7 "2025-01-10T02:40:39Z")
I think that either would work for any bodywork you plan. ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [January 10, 2025, 2:06pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/8 "2025-01-10T14:06:03Z")
> [@George\_San\_Jose1](#): > > My truck has a couple of spots like that where rust is trying to form. Very good chance the rust is even worse on the side you can’t see, by sealing it, you might make it rust even faster. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [January 10, 2025, 3:19pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/9 "2025-01-10T15:19:38Z")
Yeah, these sealers are for new car assembly or repair, not for caulking joints in old cars. ---
**Author:** ![bing](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bing/32/4619_2.png) [@bing](https://community.cartalk.com/u/bing)\ **Post date:** [January 10, 2025, 6:11pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/10 "2025-01-10T18:11:03Z")
The last and only tube of seam sealer I bought was in 2011. No idea what the chemical compound was and didn’t care but it was either ten or twenty dollars. For sealing seams on body panels. The other useful product is strip caulk. For less permanent caulking of body panels like fenders. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [January 10, 2025, 8:07pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/11 "2025-01-10T20:07:16Z")
> [@It\_s-Me](#): > > by sealing it, you might make it rust even faster. You beat me to it. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [January 10, 2025, 9:38pm UTC](https://community.cartalk.com/t/seam-sealer-dynatron-vs-urethane/198643/12 "2025-01-10T21:38:07Z")
George will sand blast, prime, seal, then paint the area. The next 10 topics: sand blasting.