I think most of us start off with bold ideas of not gluing (w/RTV) our baffles to the engine, but quickly practicality and reality sinks in. And I'm a guy that made my VS top fairing removable, wingtips as well, etc., all in the name of servicability.
The problem is unless the stuff is RTV'd to both the baffle and to the engine, the vibration and air pressure just pushes stuff out of the gaps.
Those three rivets around the doubler look a bit under-set to me...
Nope. I have measured every rivet on my bird from the start. Two holes in each rivet gauge. Min & Perfect (1.5D). If min fits, they get a bit more till they fit the perfect hole. Over 16,000. Baffle rivets are not structural. What else ya got!
I'm just not used to seeing a gap between the rivet shop head and the hole...
Me neither! I reckon they need another hit (2nd picture). We also want your plane to be perfect.
Larry, I know u have spent a lot of time creating your special RV. I have 2 suggestions:
1 use HiTemp Clear. Not that orange stuff.
2 use blue painters tape to provide an outline or border rather than just gooping it on.
Both of these will make it look much better. Get another knot or 2 out of it also.
Larry, I know u have spent a lot of time creating your special RV. I have 2 suggestions:
1 use HiTemp Clear. Not that orange stuff.
2 use blue painters tape to provide an outline or border rather than just gooping it on.
Both of these will make it look much better. Get another knot or 2 out of it also.
Really? It's a doubler on a non structural part. You guys. I'll whack them again. Can we get back to sealing holes please?
Nope. I have measured every rivet on my bird from the start. Two holes in each rivet gauge. Min & Perfect (1.5D). If min fits, they get a bit more till they fit the perfect hole. Over 16,000. Baffle rivets are not structural. What else ya got!
Back on topic, apologies; if there is a clear or gray or even black high temp RTV that is available to seal those gaps then I too think that it would be better looking than roughly applied red (and also complement your beautiful plenum). How high does the temp rating really need to be though, we should ask ourselves?!
Permatex Ultra Black is available at auto parts stores everywhere. Loctite 598 is the same product. Looks good, tough, highly adhesive.
Looks like the rivets are longer than necessary, making the appear under set. That is all I got.
Dan's method of using fiberglass impregnated with Uktra Black works great. Cut fabric to fit the cylinder area. Lay it on plastic. Smush the RTV on one side. Flip to clean plastic. Smush the opposite side. Trim off the excess plastic and apply to the cylinder fins. Allow to fully cure. Pull the plastic. Trim the excess fabric flush.
I'm going to try a similar approach to sealing these gaps.
I used the ultra-black stuff and really slobbered it on. Didn't try to get fancy. Also remember to goop up the little inter-baffle holes on the bottom. Only light that shines through from the bottom should go through the cylinder fins.
Be sure to run a tiny bead across the aluminum wrap when installed over the above. Don't want air leaking between the aluminum wrap and the outside of the RTV/glass wrap.
I have closed larger gaps with a strip of RTV impregnated glass fabric. That said, most leaks are best closed with a plain bead of sealant.
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Be sure to run a tiny bead across the aluminum wrap when installed over the above. Don't want air leaking between the aluminum wrap and the outside of the RTV/glass wrap.
I have closed larger gaps with a strip of RTV impregnated glass fabric. That said, most leaks are best closed with a plain bead of sealant.
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What are the "little inter-baffle" holes?
If I understand, you recommend a bead on the baffle that seals where the cylinder wrap begins. Correct?
Just another data point - I didn't put a single dab of RTV anywhere on my baffles. I figured I'd do it after flying to see how bad my cooling was, but it turns out I have enough cooling without sealing between the baffles and the engine.
I realize that everyone's installation is different, and this might not work for others.
Where I spent my time was on ensuring that the lipstick red silicone baffle seals are smoothly against the cowl, and there are no leaks. I've tested with ground OAT of about 35c, and I hope to get further south this summer to test things when it's really hot.
Just to help the data, would you add Model, Engine, Induction, etc. Helps to compare apples to apples.
I used gray high temp (650*) RTV from O’Reilly Auto Parts. Looks good.