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RTV application

MarkW

Well Known Member
Friend
I am working on the baffles and after paint I will be RTV'in the gaps. I think I will use black as my engine is black and I am painting the baffles black.
My question is there a trick to make the RTV look good? I have seen some pretty bad RTV jobs. I assume it would be difficult to use a tape line so I am thinking that something on the finger that will not stick would be best. In the archives I found someone mention putting water on your finger. Is there anything that works better to keep it from sticking. Maybe I should be using a glove with oil or some solvent?
Permatex talks about the Black RTV being oil resistent so it seems a little oil on the glove would help as long as you can keep it off the mating surface.

What are the secrets to a profesional looking RTV job?
 
Bare finger works fine as long as you clean the finger after each swipe.

Be sure to use "hi-temp" RTV.
 
Careful

A disposable plastic spoon works well and does not care about sharp edges of the AL that may slice a finger tip. Also a tape line about 3/16" from the lap joint or corner then bead then fillet with spoon then let skin for a few minutes before pulling tape works very well for a very neat and tidy job.
 
For applying RTV in hard-to-reach areas, I use horse syringes from the farm store. The 6 mL size is a perfect fit for the end of an RTV tube:

20130526_syringes.jpg


For clean-looking RTV application, I use masking tape to make little "dams", then clean up with an Xacto knife later if required.

mcb
 
Ultra black is good to 550 F. and the high temp 650 F. I was planning on using the ultra black also for looks.
 
Thanks I guess I was overthinking it. I haven't worked RTV since my car days and I pictured Proseal sticky. Which is too much for a finger filet. I have used quite a few syringes during the build, this sounds like another good place for one. A spoon or popcycle stick sounds good too.
I guess the more assessable spots like the ramps would be good for tape.
 
Bare finger works fine as long as you clean the finger after each swipe.

Be sure to use "hi-temp" RTV.

Mel, every time you "speak" in this forum I learn something new. Thanks.

I don't know why I just didn't use a finger for the RTV around my baffles. I guess I had the "proseal" stickiness in mind like Mark did.
 
Try a test fillet with RTV and then mist the fillet with water.... then use your finger. wipe finger often with paper towel.
 
I used the black stuff worked great. I got it in the big cauk gun tubes and the after cutting the end of the tube, I hoseclamped a piece of aprox 3/8" I.d.hose about 10" long to the end. By doing this I made all of the gap runs without wiping to produce more of the look of a weld bead.

Hope this helps.
 
I agree with Mel, the key to the finger method tho is spit! Suck on your finger and then smooth out the RTV, your finger will come out clean.
 
If you get tired of the taste of the RTV, a popsicle stick can also do a passable job in many places. Most hobby stores sell them in quantities that make them a useful, and cheap, item for many tasks... like stirring ProSeal.

I hate RTV on my fingers. Pretty soon it's in my hair, up my nose, and everywhere else. Ugh. :eek:
 
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