Adhesive and sealants - products and applications

[Karlton]

As a member of the forum, I went from saying 'well, I'll grab some caulk for that' to saying, 'let me grab the 3M 4200.'

I've also learned not to use silicone caulk on the exterior of my FWC and to use either the 3M 4200 or Sikaflex.

I also found out that there are tapes out there that will replace screws including 3M VHB tape RP25.

There are so many products out there, and I'd be interested to hear your go-to interior and exterior sealant or adhesive and what applications you use them for.

 

[Wandering Sagebrush]

Good idea for a thread!

 

[Karlton]

I realized that I didn't really follow my own suggestion!

3M 4200
This is a polyurethane product, and I use this as an exterior sealant for screws and fixtures such as the metal drain valve replacement. Followed Vic's suggestion and carry a small tube when I travel.
https://www.3m.com/3M/en_US/company-us/all-3m-products/~/3M-Marine-Adhesive-Sealant-Fast-Cure-4200FC/?N=5002385+3291170224&rt=rud


3M™ VHB™ Tape RP25
This is a double sided foam tape that I've used to adhere metal and plastic with good results thus far.
https://www.3m.com/3M/en_US/company-us/all-3m-products/~/3M-VHB-Tape-RP25/?N=5002385+3293240953&rt=rud

 

[PaulT]

Good idea!
It might also be useful to include vendor information such as pricing, minimum amounts you must order, customer service. etc. For instance, I may not need a 55 gallon drum of Sikaflex or 100 yards of VHB to touch up the sealant around the roof vent.

Paul

 

[Kolockum]

I always go between Sitka Flex and 3M 3200. Any hatch or window I use butyl tape during the instillation. Hard to go wrong with any of these options.

To coat the entire roof I use Hengs Alkyd Fibered Roof Coating.

This stuff can be bought just about anywhere RV Dealerships, Marine stores, Amazon.

 

[Vic Harder]

The smaller tubes are nice and portable. I went to use some 4200 yesterday and found I could not (even after some diligence) get fresh 4200 to come out of the tube. Only about 5% of it was used. Getting a great seal on a partially used tube or cartridge is not easy!

 

[Outnabout]

The smaller tubes are nice and portable. I went to use some 4200 yesterday and found I could not (even after some diligence) get fresh 4200 to come out of the tube. Only about 5% of it was used. Getting a great seal on a partially used tube or cartridge is not easy!

It certainly is not. I always tell myself I should just throw away the tube after I use it...the miserly part of me wins and I do not. I start a new project and then find out I can’t get any fresh material out!

 

[PaulT]

Vic,

Have you tried either double bagging in ZipLocks or sealing with a vacuum packer?

I have a similar complaint and have single bagged in ZipLock bags. One bag does seem to extend the useful life of an opened tube.

Paul

 

[ckent323]

I have a boat. Sealants are well researched in the boating community. That written there is still a lot of uniformed and incorrect opinion "shared" in boating forums and blogs on the internet.

It is important to understand which sealant/adhesive (including tapes like VHB or Butyl) to use for various materials and combinations of materials if you want the joint or whatever to last and not fail or leak. This is why, beyond competition, there are so many sealant/adhesive and even VHB tape choices. There are many different applications and materials that are best accomplished with sealants/adhesives/tapes formulated for those applications and materials.

For instance never use a polyurethane with Acrylic or Polycarbonate materials. The polyurethane attacks and damages the plastic. Similarly with acetic based Silicone caulks. There are sealants/adhesives (mostly special or hybrid Silicone formulations) such as Dowsil 795, GE SSG 4000 and Sikaflex 295 (with 209 primer) specifically formulated to work with plastics without causing damage to the plastics. I and many others have researched the sealants/adhesives to use with plastics extensively. However, the reason why these are the best adhesive/sealants for plastics and even which is preferred in a given application requires more detail than is appropriate for this comment space.

The bottom line is that sealant/adhesive selection is important relative to the materials you are using it with and the application you are using it for and therefore there is not a best one (or even 2 or 3) sealant(s).

Here are some web sites, including a few with comparison tables, that I found helpful and which have more in depth information if anyone has interest in digging deeper.


Handbook of Adhesives and Sealants (cvut.cz)


adhesivesguide.pdf (freemansupply.com)


Marine Caulking Products Guide - MyBoatsGear.com


Marine Sealant Adhesion Tests - Practical Sailor (practical-sailor.com)


sealant-table.gif (800×437) (boatus.com)


Screen-shot-2015-04-14-at-17.12.17.png (958×698) (timeincuk.net)







Craig

 

[Dadocut]

Craig, Those are great resources. I've used BoatLife's Life Seal. It's been great for sealing around hatches as it stays soft and can be lifted out with a putty knife so one can repair/replace the hatch or what not. It's not good to get it on your skin though. The fellow I bought my Hallmark from said Hallmark recommends it.

I'd add Whitlam's Blue Magic thread sealant to your list. Threaded fittings, particularly plastic threads, have caused me all sorts of problems with plumbing. I always thought one was to use teflon tape. This article (https://www.linkedin.com/pulse/what-thread-sealant-use-pvc-fittings-larry-workman) explains why teflon tape is a poor choice. The article states one needs four things for sealing plastic threads in a water system:

• safe for plastic (many are not)
• non drying (allows one to adjust the threaded fitting for alignment after tightening it)
• non lubricating (otherwise it's too easy to over tighten the plastic threads. Many sealants have teflon or PTFE for lubrication).
• Water safe (i.e. meet NSF 61 standard)

It's surprising how hard it is to find something that meets all four requirements. Nothing from Loctite, Rector Seal, or Permatex fit the bill. Whitlam's Blue Magic Sealant was the only one I could find. So far it's worked great for me.

 

[huskyrunnr]

A friend who was restoring an old airstream gave me some parbond to try out on my Alaskan camper. I find it much easier to apply than other sealants I’ve tried.

 

[DavidinPhx]

Some great info here! FWIW, my Ovrlnd Camper popup builder uses and recommended to me 3M 540 sealant/adhesive. Works great other than the limited open life others have mentioned. supposed to be very UV resistant— we’ll see how it goes in Phoenix …

i called 3M on recommendations for VHB that could stand very high temps. Finally got to a VHB technical specialist who recommended 5952. very high temp tolerance — 300°! Also very wide range of surface energy adherance. Seems to stick incredibly well on every thing, especially with Primer 94 adhesion promoter. The key is to clamp/roll it well and let it set for 24hrs.

 

[ntsqd]

For stuff like non-potable water and other pipe fittings I use Lock-tite 545, but in some cases I use Hylomar. Hylomar is a non-hardening polyurethane blue goo that will NOT easily come out of clothing. You were warned! My local CarQuest stocks it, but not all of them do. Never seen it at any of the "big box" auto parts stores.

For an exterior sealant I un-apologetically go straight to 3M 5200 in most cases. Not a fan of any type of silicone sealant except for the "Right Stuff", but that is more for mechanicals like engines and axles than camper stuff.

 

[smlobx]

I recently started researching VHB tape as a possible method of attaching our new solar panels to our roof. I found that the manufacturer, 3M, has a wealth of information on their website. I was even able to reach out to one of their technical staff who got back to me the next day. There really is a lot of science behind the product.

https://www.3m.com/3M/en_US/vhb-tapes-us/