LAME question: Window seals on unpressurised singles

[PlankBlender]

Here's a quick one for the LAME's and DIY pilots out there:

The window seals on my late 70's Archer are a bit grotty, which in drier parts of the country where the machine used to live didn't really matter, but with the recent heavy rains in Queensland, I've had to shovel out a few inches of water from behind the front seats, and of course this isn't really great for the interior or anything else in the machine for that matter.

Question here is can I just take some run of the mill silicone sealant and replace the old gunk, or is there some sort of rule that would prevent me from doing so? Am I running the risk of making things worse by taking this into my own hands, are there any alternatives (other than getting the custom cover which is on the to do also)?!

Cheers! :ok:

[MyNameIsIs]

Sched 8 maintenance in the CAR's of what a Pilot is allowed to conduct includes removal and resealing of side windows in an unpressurised aircraft.

May as well take the time to take yours out, clean them up properly and re-seal. Day job, two days if you REALLY want to clean everything up (that is, getting a steel brush to the frame then spraying some primer to protect them).
Done it on a PA28 body before whilst learning a thing or two, wasn't too hard. Funny thing was, the pilot's windshield - which a LAMEy fitted - leaked and mine didn't!

Use Sikaflex.

[tail wheel]

"...take some run of the mill silicone sealant..."

Careful! Some silicone sealants are corrosive around aluminum! :=

[Chimbu chuckles]

DONT EVER use a steel/wire brush on your aluminium airframe...unless you want to ruin it. Microscopic bits of steel will break off and be left behind in the aluminium...very, VERY bad news.

Use scotchbright.

Don't just use any old sikaflex type material...one type is compatible with aluminium and the other will literally eat the metal away completely. Look at the leading edge rib in my vertical stab for where some moron got lazy and instead of using the rubber grommet that is just inches away put silastic there instead...it has dissolved the first couple of inches of rib.

http://www.fototime.com/{9010FC65-ED8F-4EBF-BA39-337EEF48A194}/picture.JPG

By all means do it yourself if you want to but get professional advice first.:ugh:

[mootyman]

Please don't use standard silicone or sikaflex. If you feel the need to do it your self order some pr1422 or ps 870 (which has chromate in it to prevent corrosion).

I know it is expensive but maybe there is a maint facility close by that has some expired P.R. which would be fine and a lot better than using sikaflex or any other sellys product.

PS870 is about $75 a tube which when put down right will prevent corrosion around he window and also prevent water getting in and corroding the floor.

It will be money well spent in the long run and since it will be right there in the eyes of casa if they ramp you it will save you a lot of embarrassment.

[employes perspective]

your window may of sealed and the lame fitted one leaked,but at least the ali frame that is holding it in position (lame window)will still be there in a few years as for your repair it will become very costly.....Pay cheap ,pay twice:}:}:}:}:}:}

[bushy]

I found that Pipers still leaked and accumulated water on the floor even when they had a canvas cover covering ALL the windows and windscreen.
They often sit nose up a bit, and I think the water came in through the air vents from the leading edge of the wing to the floor level air outlets.

[RadioSaigon]

Damn fine thread :ok:

Perhaps someone (with a valuable tip like this threads) should start a pilot maintenance thread, highlighting the pitfalls and lessons learned!!! We could all benefit from that!

[Old Akro]

Silicon can also be detrimental to the perspex. Silicon is not silicon and there are different cure types. You can see fine cracks around the eddge of some aeroplane windows. In many cases this is caused by the use of silicon. Lp Aero are recommending the use of Bostik 1100FS Fast Set Polyurethane Sealant.

[Sunfish]

Most silicones use an acetic acid cure mechanism (you can smell it) that eats aluminium. It's not suitable ever, get some PR1422, its messy to use and although once your stuff is stuck in you will never get it out in one piece, but that shouldn't matter.

[MyNameIsIs]

Looks like I may have been given the wrong advice by the LAMEy that showed me what to do......

If in doubt, ask your LAME what he would be doing..

[Short_Circuit]

I can just see the log book now. :}

Report
"Cockpit windshield seals in poor condition"

Action
"Windshields resealed IAW pprune.org/d-g-general-aviation-questions/369888-lame-question-

[PlankBlender]

Short_Circuit, nice one :ok:

Everyone, thanks for the advice, as always just what the doctor ordered :}

Old Akro, where would one get some of that Bostik 1100FS stuff? Seems it's what Piper recommends also, so I might just go with that..

[Kulwin Park]

Plank Bender, I'm a LAME, and I would be using PR1428 if you can get your hands on it? Tho it dries a deep purple colour, it is highly flexible and UV resistant, specifically made for windshields, especially floating ones like Cessna's, or Piper windows attached by screwed on tabs.
The PR1422 is brown in colour when dried, but was made for fuel tanks and degreasing resistant, tho not very UV or flexible when aged cured. It would do for several years, but PR1428 would be better. Then you could also apply 2-pack touch-up paint via a touch-up brush over sealant. Job would be very presentable & professional :ok:

The Bostik stuff that others are talking about, should be of Neutral Cure only, and would be found in a Paint Trade Centre outlet of some sort. Neutral Cure marine sikaflex would also be allowed, and it maybe a pre-mixed colour the same as your pre-coloured to your aircraft paint work. :}

Personally I'm fussy in those situations of windows, and would only use a plastic or phenolic or nylon scraper to remove old sealant. Just remove the remaining sealant with Isopropanyl, Toulene, or a goo remover. Don't be scratching it like others recommend!!!! Why scratch a good fine surface unless there is corrosion there??!! Scratching an alodined coating off alloy would be like scratching your skin with a knife blade to make sure old skin cells were removed, tho no cancer there :confused: ... Unless corrosion, just clean surface, and re-apply. Perfection is for visible areas, and without a trained person or eye on job, all your doing is prompting future problems.

NEVER USE A WIRE BRUSH!!!! :ugh: ... maybe if you PM me, we can talk on phone, but you should be alright with the above directions.

PS - use a good quality masking tape, and not too large a filler bead of sealant, just enough to do the job of keeping the water out, and not enough for the sun to harden, and your washing methods to risk catching the bead of sealant off. ;)

[tail wheel]

Now discovered why not to use Silicone sealant around aluminum - it has a ph of 8.85, thus is very alkaline and would corrode most metals.

[Jabawocky]

Yep:ok:

A Neutral cure and SIKA make the good stuff is the way to go for most jobs.

This is the stuff I think the LAME's want you to use. Bunnings do not stock it! :}
http://buyat.ppg.com/REP_aerospace_files/Sealants/pr1428a.pdf

[bush mechanics]

You will find sealants at Bunnings.Look for the Selleys No More Skills Bar.It should be labelled "Aeroplane in a Tube " or possibly "Instant Airframe"

[KittyKatKaper]

and FFS be carefull when rescrewing any bolts or screws..........
Those connection points probably haven't moved in 10 or more years and are now just a congealed amalgam of metallic salts...... meaning that it is extremely easy to strip what still remains of any thread.

[Old Akro]

Bunnings range is sealants is c**p. Basically they only stock building type sealants. I'd be trying a car paint or crash supplies shop.

[Connaught]

lmao

love this ****, keeps me employed,

your Archer wasn't built by Massey-Ferguson


use whatever you want from where ever you want at the cheapest possible price you can get it

the PROPER stuff is more than likely a a PRC product, they are expensive relatively speaking, , but if used properly do NOT cause the damage mentioned in previous posts,

1422 works well for everything (ask bombardier, embraer and boeing) but sticks like **** to a blanket, makes window removal a pain in the arse, put a piece of string in it so the next guy can pull the string out and thereby cut the sealant

or 1428 the cool purple stuff that is 'low adhesion' makes the window come out easier, i have also used it to seal floor boards

if you are dead set on being a tightass buy some rtv 1345 at least, it comes in 3 colors

and please use the steel wire brush to clean up the frames, better yet get an angle grinder the hole for the window will be enlarged making it better, however a plastic or phenolic scraper sharpened on belt sander will do the perfect job

if the screws are rusty and siezed, drill em out and replace em, screws are pennies each, so are the nuts

another option is simply put a bead around the edge of the window and frame, without removing the window, this has the benefit of doing the required sealing, and not making a mess out of the window when you try to remove it, and frankly would be my first go , however i would use the proper sealant and masking tape, and in this case any masking tape will do

this is why engineers are engineers

:mad::mad::mad: hell

[Chimbu chuckles]

Connaught I have spent many, MANY 1000s of $ correcting previous work done by 'engineers' over the years. What do you think put that crap in my vertical stab?

LAMEs range in skills and talent from awful to excellent just like EVERY other profession.

So perhaps just tone it down a tad...lest us aeroplane owners start recalling every horror story we have ever experienced with ****e LAMEs costing us cubic $ or making premeditated attempts on our lives:ugh:

[PlankBlender]

Interesting discussion here, I've asked my current LAME also and he seconded the tank sealant idea, in his experience that has worked best in the past. Again a messy job, but apparently worthwhile.

Connaught, the plan had been all along not to take the windows out, I didn't want to make the job that big if it wasn't totally necessary.

I'm in two minds at the moment, I'm leaning towards the 'neutral cure not so messy sealant' option in conjunction with a cover, with the cover of course having additional benefits protecting the interior from fading and the avionics from heating up too much on a hot QLD day..

[Arnold E]

How much is your Archer worth, 50 - 70k? I find it difficult to comprehend aircraft owners that are prepared to "save" maybe a few dollars on what is, in real terms, a very expensive "investment". You have been given some very good advise here. I would use the 1428 myself despite the extra cost. At the end of the day you would probably save <$100 in
an overall cost of how may thousands of dollars?:confused:

[RadioSaigon]

...lest us aeroplane owners start recalling every horror story we have ever experienced with ****e LAMEs costing us cubic $ or making premeditated attempts on our lives...

ROFPML! Oh yeah, that's several pages of thread just there!!! Loose cylinder head bolts, plug/mag leads off or unsecured, fuel systems left disabled, torque wrenches left in the float-plane cowls... <sigh>

There'd be some colourful reading (and comments!) in a thread like that I reckon!

[PA39]

Sikaflex - 227 available from Repco. PM Tnuc he's the best LAME in Oz....bar none!!

[Kulwin Park]

lest us aeroplane owners start recalling every horror story we have ever experienced with ****e LAMEs costing us cubic $ or making premeditated attempts on our lives

Hey Chuckles, do you know any good LAME's?? Or have anything good to say about them?? Just wondering who you take your aircraft to, coz obviously you believe we are all not highly skilled enough, or give sound advice ....

What is your profession?

[Chimbu chuckles]

KP yes I do know some good LAMEs...lots in fact. My post was purely aimed at connaught who seemed to be having more of a 'go' at the thread starter than seemed reasonable.

I have been flying for near 30 yrs and professionally since the mid 80s and have owned two aircraft. I am currently restoring my Bonanza ground up, and I DO MEAN ground up!!

As a part of that process I am doing the vast majority of the work and am essentially 'apprenticed' to an extremely good LAME and I count several others as close personal friends.

Having said that I have been exposed to some absolutely horrendous LAMEs over the years both in my professional life and as an aircraft owner.

You're not suggesting that LAMEs defy human nature and are all fantastic are you? That would be like me saying every professional pilot I have ever known met very high standards...I could not say that and keep a straight face.

If you want just one example of gross stupid go back to the first page and view my first post in this thread. There is a picture of the internals of my vertical stabilser as I de-mated it with a glob of silastic either done by a LAME or signed off by a LAME to stop wire chaffe when the rubber grommet is close by...I had to buy a new rib as a result...the front of that rib is just not there anymore. There have been many other instances where the LAME's that work on my aircraft now have shown me stuff done over the last 38 years by LAMEs or signed off by LAMEs that just beggars belief...even they shuffle their feet uncomfortably..another example? When we removed my horizontal stab last year we found it had been off once before and when reinstalled they used the wrong bolts. 26, from memory, new bolts ordered...all of $2 each:ugh:

I remember picking up my 185 in the early 90s from having a 100 hrly...all set to go they said...what are those bits laying on the floor over there? Come back in 3 hrs they said.

Once I was a CP of a charter operation and had to deal all the time with a 3rd party maintenance organisation...got a phone call from the head LAME one day when one of my pilots was there picking up our Islander..."Your pilot just threw things at me and called me a useless fcking cnt!!"

Really:D...he's usually pretty laid back...I'll talk to him.

Turns out the broken seat back that was written up was pencil whipped, along with a bunch of other write ups, and had collapsed on him on takeoff...just airborne...I rang the fella back and called him a ufc as well.

They fixed the seat.

Then there were the LAMEs at an airline I worked for flying F28s who not once but twice caused, through shoddy maintenance, main gear legs to snap off - YES SNAP OFF - on landing...not me flying them thank fck...but I was flying it the day we almost lost it because they hadn't refitted the wheel speed generators after a gear leg change - dual inspections all signed off of course...no wheel speed generators means no brakes at all on that side at any speed over 11kts....made for a REAL interesting landing.:ugh:

So as I said in my last post...LAMEs run the the same gambit of human failings as every other profession...some are brilliant, most are very good, and some would be a waste of urine...so (connaught) be a bit more gentle with questions from us dumb owner pilots.

Thread drift off.;)

Edit; And just for balance I have also worked at companies with truly first class LAMEs, both GA and airline, where you REALLY could not fault the care and feeding of the company aircraft:ok:

[PlankBlender]

Arnold E how are you concluding that I'm out to save a buck? :=

I just happen to be one of those owners who has a bit of time on their hands and who loves to learn about all things aviation. The advice I get here is invaluable, there's a great big pool of experience out there that would be dumb to ignore..

:ok: for all the advice!

[Kulwin Park]

chuckles, all good. I know as a LAME that I've seen some work that rates so badly and shoddy, that I wished sometimes I had dobbed in people. This industry seems to attract its fair share of idiots, so I just stay clear of the ones I'm unsure of. When I carry out a 100, I really don't trust anyone's work, and pull off all panels necessary, unless I did it last time. I'm fussy, but as you say, some are not :/