I bought like 6 tubes to redo my trim and around my front cap on my class c. The original owner used clear silicone on the front cap and it looks horrible. I also have a few crackes/ issues on some of the other spots. I cleaned all the silicone off and used a small bead of dicor 551, then wihtout knowing i tried to smooth it out. well it got everywhere. I cannot run a perfect bead and this got old real quick. it took me longer to clean up my mess that it did to remove the silicone. What can i use that will let me smooth it out? I know you are not suppose to use silocone....but this dicor is not gonna work for me.....

Tape it off with that blue painters tape first then lay the bead. Get a rubber caulk tool at one of the big box stores and use it to smooth out the joint then remove the tape.

How did you try to smooth it? Sikaflex 221 smooths really well with a finger kept wet with soapy water.

lynndiwagon wrote:Tape it off with that blue painters tape first then lay the bead. Get a rubber caulk tool at one of the big box stores and use it to smooth out the joint then remove the tape.This is exactly how I do it and it ends up looking like a machine did it - perfect.

First off........silicone will not even stick to siliconeSO you would have to use a 'silicone cleaner' to get completely rid of the silicone residue before ANYTHING will stick againAlso check the expiration date on bottom of tube

i went to lowes tonight and got some sealant that does not say silicone on it and is good for fiberglass and is good for light "tooling". The painters tape might be the way to go i just have so much to do......I did forget to get silicone remover...took forever to get the stuff off

Dicor 551 for trim, it sucks | Good Sam Community

westend
Explorer
Aug 14, 2018
I make different cuts (angles and opening sizes) on the ends of the tubes for the job. I also use the wet finger and wooded tongue depressors cut at a angle or radius for the job.
This eliminates 90% of problems when making an even bead. 10% is pressure within the gun and the amount of material laid down. If using a very small bead of material (1/8"), a wetted plastic spoon is a good tool to spread the material. Remove any material that sticks to the spoon, every foot or so. I have special spreading tools but typically use my finger for most work.
JIMNLIN
Explorer III
Aug 13, 2018
I've found Dicor 501 or 551 is as easy to use as any other sealant.
Having a part time mobilhome/rv repair business we specialized in structures and exteriors.
It takes practice and patience and experience to make a seal job look professional, if your picky.
Pages and pages of you tubes on the subject to gain ideas.
I would practice on a short foot long section . That way if it comes out krappy it can be quickly cleaned up while its still wet. I make different cuts (angles and opening sizes) on the ends of the tubes for the job. I also use the wet finger and wooded tongue depressors cut at a angle or radius for the job.
goducks10
Explorer
Aug 12, 2018
I've used Dicor as well. It does suck. I called Northwood MFG and they told me they used the Geocel 2300 for the front cap to sides caulking. I found some at the local RV dealer. It's way way nicer to apply than Dicor. Flows much easier. You can stop and start in the middle of a joint and it hardly shows.
Goecel is not recommended for EPDM though so its back to Dicor if I need to do any of the roof areas. I used Eternabond on the roof where the top of the cap meets the roof.
dapperdan
Explorer
Aug 12, 2018
As brought up earlier, you're going to have to remove all of the old silicon sealant. Here's what the "pros" use.

Once all of the silicon has been removed you'll want to use THIS, again this is the product the pros use. This product can be purchased on the net or at your local RV repair shop. I believe it's the industry standard as far as sealing seams and joints on RVs is concerned. It's what Twin Lakes RV Repair used on our rig a couple of years ago when we had the whole rig re-sealed.

Dan
oldschoolhdmike
Explorer
Aug 12, 2018
i am going with my original statement...551 sucks....i did the tape method which did ok.....but the seems still to me do not look good. it looks like from the factory they used clear, not sure if it is a silicone or not but it looks fine so my best bet is to go back with something clear....and that is "toolable" i also did the spray method on this 551....it still sucked....it does look ok in spots but using white is just not the way to go....ill post some pictures of the previous owners silicone job. i may just take it to a rv shop and have them do it....
goducks10
Explorer
Aug 12, 2018
oldschoolhdmike wrote:
goducks10 wrote:
Get a spray bottle. Fill it with water and a drop or two of dish soap. Lay the bead, lightly spray the bead, wipe with your finger.
Just did my whole front cap and it was the easiest caulk job I've done. Trying to smooth it out without any wetness just makes the bead drag and stick.

you did this with 551 dicor?????

No, I used Geocel 2300 MHRV clear
oldschoolhdmike
Explorer
Aug 12, 2018
goducks10 wrote:
Get a spray bottle. Fill it with water and a drop or two of dish soap. Lay the bead, lightly spray the bead, wipe with your finger.
Just did my whole front cap and it was the easiest caulk job I've done. Trying to smooth it out without any wetness just makes the bead drag and stick.

you did this with 551 dicor?????
goducks10
Explorer
Aug 12, 2018
Get a spray bottle. Fill it with water and a drop or two of dish soap. Lay the bead, lightly spray the bead, wipe with your finger.
Just did my whole front cap and it was the easiest caulk job I've done. Trying to smooth it out without any wetness just makes the bead drag and stick.
oldschoolhdmike
Explorer
Aug 12, 2018
i went to lowes tonight and got some sealant that does not say silicone on it and is good for fiberglass and is good for light "tooling". The painters tape might be the way to go i just have so much to do......I did forget to get silicone remover...took forever to get the stuff off
Old-Biscuit
Explorer III
Aug 11, 2018
First off........silicone will not even stick to silicone

SO you would have to use a 'silicone cleaner' to get completely rid of the silicone residue before ANYTHING will stick again

Also check the expiration date on bottom of tube

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Dicor 551 for trim, it sucks

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