Sealing method, cure time

Ready to seal the firewall lower and shelf sections with the Flamemaster CS-3204 B2 sealant. From reading through many (too many?) posts on the subject, I still haven't satisfied myself that I know what I need to. Any help will be appreciated.
I intend to apply the sealant, cleco 100%, then come back and rivet when the sealant is partially but not fully cured. Does anyone have a reason why it can't or shouldn't be done like that?
What kind of cure times can I expect with ambient temps ranging from mid 70s to high 40s, day to night? I haven't found any cure time data for this product. Is there a chart somewhere?

I do not see a problem with your plan. I myself would leave the clecos for two to three days. Just keep an eye on the curing, I leave some on a tray with a stick in it and monitor how it is curing.

I just recently did mine. I just mixed up one of the small containers of Pro-seal, smeared a thin layer on the top of the lower firewall flange, clecoed the shelf in place and then riveted. The next day it was cured enough that I was able to trim the squeeze-out with a razor blade. I was surprised how much squeeze-out there was.

I think your plan would work fine as well.

Jim

When I built my gas tank I remember that it was about a week to fully cure.

Ah...found it!

Thanks gents for the responses. On a subsequent attempt I was able to conjure up a web page with an actual data sheet. Don't know why it didn't come up on the first try. I could be convinced that all this internet stuff is less ones and zeroes and more chicken bones and cat entrails. That at least would explain why all those IT folks do their "major maintenance" after midnight. Hmmmm?the moon is full tonight, too.

Anyhoo, here's the data sheet with the cure time chart?
http://www.flamemaster.com/Technicals PDF/CS3204 rev 01-07.pdf
It indicates the target time for riveting would be more than 24 hours and less than 72. Should be good enough to get it right.

Fuel tank sealant is not fireproof. I think the thinner the better, whether the firewall or fuel tank. I would not wait for the sealant to partially set up, but would rivet soon after applying sealant. If I am wrong, it will be interesting to learn why it is better to let the sealant partially set up before riveting.
Joe Gores

Mich48041 said:

Fuel tank sealant is not fireproof. I think the thinner the better, whether the firewall or fuel tank. I would not wait for the sealant to partially set up, but would rivet soon after applying sealant. If I am wrong, it will be interesting to learn why it is better to let the sealant partially set up before riveting.
Joe Gores

Click to expand...

I agree.
The rivets pull parts together with much more force than clecos. The intent of sealant on the seams is primarily to seal for fluid penetration. I see no benefit delaying the riveting. The thinnest coating possible is the most desirable.

XOverZero said:

Ready to seal the firewall lower and shelf sections with the Flamemaster CS-3204 B2 sealant. From reading through many (too many?) posts on the subject, I still haven't satisfied myself that I know what I need to. Any help will be appreciated.
I intend to apply the sealant, cleco 100%, then come back and rivet when the sealant is partially but not fully cured. Does anyone have a reason why it can't or shouldn't be done like that?
What kind of cure times can I expect with ambient temps ranging from mid 70s to high 40s, day to night? I haven't found any cure time data for this product. Is there a chart somewhere?

Click to expand...

John,

Did you use the Flamemaster sealant for sealing the shelf to the firewall (page 22-03 Step 4)?

Bob

Hi,

For sealing the rivets neatly, I used a "EK Tools" 3/8" punch to punch a hole in masking tape. I made little squares of tape with a hole in the center and applied the tape around each rivet. After applying the sealant, I let it cure just a bit, and then removed the tape. The tape is easier to punch if you double it over, punch, then separate. The tape is easier to remove quickly if you double over a bit of each piece. This makes a tab which is easy to grab and pull off.

The punch is available in various sizes for around $5:00.

http://www.amazon.com/EK-Tools-Circ...8&qid=1393023015&sr=8-1&keywords=ek+tools+3/8


Good Luck

Joe's "little holes in tape" is a great way to keep the ProSeal mess at a minimum -- and the end result looks sharp too. I was too cheap to order a punch so I just used straight pieces of masking tape to "box" each rivet. My firewall has lots of neat ProSealed "boxed" rivets as opposed to Joe's ProSealed "round" rivets. Works fine either way.

In a multitude of counselors there is safety.

Ron B. - "...leave some on a tray with a stick in it and monitor how it is curing."

Thanks Ron, did that.

Mich48041 - "I would not wait for the sealant to partially set up, but would rivet soon after applying sealant."
rvbuilder2002 - "I see no benefit delaying the riveting."

Joe and Scott, OK you sold me. I riveted and it wasn't a mess at all. Good call.

bhassel - "?Flamemaster?"

Yes, Flamemaster CS 3204 B2

LittleJoeA - "...little squares of tape with a hole in the center and applied the tape around each rivet."

Exactly what another builder recommended, and I saw the results on his plane. Heck yeah!, er?I mean wilco.

Timely that this post popped back up to the top today, as I just got back from doing the deed?and all is quite well, thank y?all very, very much.

Besides the recommendations received here, I also asked around. (Living in a part of the country that can be understated as being an ?RV rich environment? has its benefits.) In addition to sealing the joint between the lower firewall and the center shelf part, I wanted to run a bead along the bottom where the lower firewall joins the floor and sidewalls. Pal Jimmie from a couple hangars rows over suggested using thin line tape to mask the sealant area. So I did. Great idea.

Last weekend I had the pleasure of meeting Roger, a fellow -12 builder, and got to look over his nearly finished plane. Besides getting some sage advice about sealing the firewall, I also got to abandon any hope of snagging a Lindy?not next to his plane anyway. Drop dead gorgeous it is. He was adamant about using veterinary hypo syringes to apply the sealant. So I did. Another great idea.

I had already changed my mind about riveting based on feedback from Joe Gores and Scott McDaniel, noted above. Glad I did, too. Between the fine line tape and the syringes, there was no mess to get in the way of popping the rivets. I didn?t even get any sealant on the pullers - not even a spec.

Wow!

Thanks John.

My mother would be proud.

RV12Roger

what is the difference between Flamemaster and Pro-Seal?

Flamemaster

According to Van's Catalog, Flamemaster replaces the older Proseal sealant. 2BK