What kind of sealant

[djw2112]

I forgot which kind to get.  If i am going to redo the exterior molding around the outside of the 5th wheel (not roof but body) i forgot do i get silicone or non-silicone sealant?  Its time to do alittle maintainance and i want to be sure i get the best kind for the job.  I did some small patch work last season and that product was suppose to be clear but it has gathered dirt and now looks like hell.

 

[Gary RV_Wizard]

A non-silicone (or a silicone blend) is usually best for side seams.  Geocel Proflex RV is one good choice, but you can get a exterior window & door sealer (caulk) at a local home center taht will work fine.

 

[djw2112]

Thanks Gary 

 

[Broke Boater]

Building/restoring ,,,and I get a lot of friends bringing me their boats for repairs,,, is my retirement job.  I'll throw this out there also, 3m uv 4000. It's a top of the line marine sealant. It's formulated for a marine environment and the uv formula wont yellow from the sun. There is two 4000 from 3m, I use the uv version. It'll seal and adhere to wood, metal, Aluminum, plastic. I buy it online to save money. Definitely don't use silicone where its exposed to sun,,,gregg

 

[Gary RV_Wizard]

The 3M 3000  UV and 4000 UV are great products.  So is the 3M Body Seam Seal, used on many fine automobiles. Both are premium priced but very high quality.

 

[boatbuilder]

Second the 3M 4000UV.

 

[djw2112]

Thanks guys...

The bigger issue is that with the storms we have around here which come with rapidly changing wind conditions it seems to blow the water up under the side panels and it gets up inside the wall.  I have already had to patch one seam because it had soaked the floor of the wall inside, once i sealed the seam the leak stopped and i was able to salvage the floor from rotting.

I think the sidepanels have two parts, the guide and the sleeve.  The guide should be made to overlap the sleeve when the panel is slid or hooked into place on installation so there should be no water being able to get up inside the connection, but it does.

I was thinking about getting a small piece of flat wood just big enough to hold in my hand and going along the seams and lightly tapping on the wood as i go accross the panel seam to help compress the seam better, but i dont know if that is a good idea or not.

 

[AStravelers]

Don't forget.  If the old sealant is silicone you MUST get all the old silicone off before adding new sealant.  NOTHING sticks very well to cured silicone.  Use Acetone to soften and remove the old silicone.  Be sure to use gloves rated for heavy duty chemicals.  Nitrile gloves won't work. 

 

[Gary RV_Wizard]

Acetone is a good performer but risky to use anywhere near a painted or plastic, fiberglass or rubber surface. It dissolves all of those quite well!  Ditto for MEK and lacquer thinner. Be careful!!

 

[AStravelers]

Yep.  Acetone is pretty nasty stuff.  It pays to be careful.  Also extremely flammable.

Just be very sure to get off ALL the old silicone, no matter what method you use.  100 or 150 grit sandpaper works pretty good once you get the major part of the silicone off.

 

[chuckbear]

Acetone is a good performer but risky to use anywhere near a painted or plastic, fiberglass or rubber surface. It dissolves all of those quite well!  Ditto for MEK and lacquer thinner. Be careful!!

I've used acetone on fiberglass for decades with no adverse effects. But do be careful on other surfaces. Chuck

 

[AStravelers]

I've used acetone on fiberglass for decades with no adverse effects. But do be careful on other surfaces. Chuck

My experience as well.  As long as the acetone is not pooled on the fiberglass and left to sit there.

Additionally when removing silicone, even from painted surfaces I use acetone.  I am going to be putting sealant back on the painted area I removed the silicone from so I am not overly concerned with the minor amount of damage I am doing to the paint or clear coat.  Besides using a rag or paper towel to wipe/scrub off the silicone and then quickly drying off the acetone (usually air drying works just fine) doesn't do that much damage to the paint.

The important thing is to get the old silicone off so the new sealant will strongly adhere to the paint fiberglass or whatever. 

As side note.  I never put silicone sealant back on.  Simply because if the silicone needed to be replaced then sometime in the future you may have to reseal that same area.  So much easier to remove the old, non-silicone, sealant and not have to completely remove all the old sealant.  Doing a good job of cleaning up the residue usually works just fine.