Removing screws locked with pressurised cockpit sealant?

[Fooman]

Good Morning/Evening.
I have and Aerocommander 685 twin that I am turning into a simulator. Due to requiring access between the inside of the cockpit and under floor, I need to open up the floor. Most of the centre panels are merely screwed to the floor framework, but as it's pressurised, everything was sealed with some sort of sealant. I have tried drilling out and using an easy out, but my drills keep breaking or blunting. I got so deparate that I went at the floor and used cutters to tear it up. Problem is I still have to seal it.
Is there any way of dissolving this compount, whatever it is, or removing the screws. Any thoughts? Thanks in advance for any replies.

Rob
Melbourne, Victoria, Australia.

[grounded27]

If you can not extract (thinking you have not broken a drill bit or ez out)Use a drill bit the same size of the shank to pop the heads off. Since your use is for a sim why would you be concerned with sealant? I would use a sharp metal scraper ( on an aircraft we have hard plastic devices we use).

[Fooman]

Not concerned with the sealant, and thought of popping the rivet, but that will just make the whole bold and nut spin. May have to use an angle grinder. Hope not to.

[helicopterray]

Apply heat. If there is a sealant, it will soften with heat, allowing you to unscrew.

[cockney steve]

A cobalt-steel drill will go through even a hardened ball-race.
Don't buy cheap far-east stuff. use the correct speed.....that sorts the blunting-issue (almost) Too- little pressure /too high a speed causes the cutting -edge to skid, overheat and go soft/blunt.


Breakages usually caused by too much pressure, failing to ease pressure when the tip sytarts breaking-through , pushing too hard on an offset handle (old B&D machines had a handle under the motor) put the pressure right over the chuck-centreline,otherwise the tendancy is to bend the drill....they snap!

If the sealant is unsightly....try a heat-gun ans scraper...if it's silicone based, silicone dissolver is available at DIY stores in standard cartridges....if it's solvent-based try cellulose thinner (gunwash is cheapest) primarily Acetone, it's at car-paint stockists. hth

[Krystal n chips]

Not taking the proverbial here, but, what you need are :

old dental picks for the sealant.

M.E.K

Speedbrace with the correct bit.

"Easy out", if you can drill the hole to sufficient depth to get the shaft to "bite" that is. As cockney steve says, invest in some decent cobalt drills here.

"Grolly bar"..if you can source one or know a tame engineer who could help you source one.

An angle grinder is the very last resort I would suggest.

Let us know how you get on.

[BeeBopp]

WEICON Sealant + Adhesive Remover (Spray) (http://www.weicon.com/pages/en/products/spray/cleaning-degreasing/sealant-adhesive-remover.php)

This stuff will dissolve PRC sealant (be careful with it)

Then get yourself one of these

El Brutus Johnson Bar Screw Extractor - YouTube

and use it with this

EzGrip :: screw extraction, friction drops, screw removal (http://www.ezgrip.net/faq.html)

Problem solved !

[Fooman]

Thanks for all the suggestions. Will try heat, then sealant remover, then getting some decent drills if those don't work. Dont know what a golly bar is, but I'll google it.
Many thanks and I'll let you know how I go.
Rob.

[Alber Ratman]

As your composite floor isn't going to fly again, so a little bit of delamination if it happens isn't going to hurt and if you have a rivet gun and shop air, get yourself a rattler (screw impact remover, screw shaker or T Bar Snap being other local names )

Google Image Result for http://www.handsontools.com/assets/images/10858_14427.gif (http://www.google.co.uk/imgres?q=screw+impact+remover&tbm=isch&tbnid=8lG_U6AWNsba0M:&imgrefurl=http://www.handsontools.com/Wivco-TH28000-SHAKE-N-BREAKTM-Air-Impact-Screw-Remover_p_8765.html&docid=pWvgDEJdvaa7nM&imgurl=http://www.handsontools.com/assets/images/10858_14427.gif&w=291&h=234&ei=CQBzUYyiFYnVPKrqgXA&zoom=1&biw=1280&bih=599&iact=rc&dur=625&page=1&tbnh=146&tbnw=156&start=0&ndsp=20&ved=1t:429,r:9,s:0,i:113&tx=78&ty=24)

Don't use it on composites you want to see flying again mind, not good for structural integrity..:E

[Chock Chucker]

Since your aircraft wont be flying again & wont need to be airworthy if you dont want to drill out all the screws on the floor boards in the cockpit then you can always cut openings in the floorboards with say an angle grinder or a pneumatic grinder with a rotating cutting tip. If you do this make sure you wear saftey glasses & a breathing mask as you dont want that stuff in your eyes or in your lungs. Try not to cut through any floor beams as you will need these to hold your old/new floor up.

Once you have gained access below the floor boards to do what you need then you can make dummy floor boards out of 10 milimeter thick ply board to go over the top of the cutouts where the old boards used to lay, maybe throw a few screws back in to hold it all down & in place & paint the boards flat black if that was the origional colour. You can also lay wing grip on the ply board flooring which is a no slip tape or paint you can buy.

You can easily do the whole cockpit flooring like this just so long at it doesnt effect the movment of rudder pedals or any other things that may be around floor level as it will lift the cockpit flooring by another 10 Milimeters or (1 CM).

No one will know if done looking professionally & it may be your easiest & cheapest way to go about it especially if the old screws are really difficult to get out & make it impossible to lift the cockpit floor boards.

As someone else had mentioned to use heat on the sealant. This does work well so best to use a heat gun or if you dont have that then you can always borrow your mum or sister hair dryer but if your using it for a long time it may burn out the motor.

Place a lot of heat on the sealant & it should become more rubbery & easier to scrape out & pry up. A jemmy bar & some flat blade screwdrivers can help to pry up the floor boards once sealant is rubbery & screws removed but be careful not to break your floor board while levering it up.


All the best & keep us posted on your outcome.

Chock Chucker.

[Fooman]

The floor isn't composite, it's alloy. I don't want to ply over the old floor as I still have the original seat runners, and it would just complicate things further down the track. I will start with the less destructive methods first and excalate from there.
Thnks guys.
Rob.

[Chock Chucker]

No worries Rob,

Sorry was unaware flooring on that type aircraft is alloy. Well that makes it easier if you still cant get floor boards up with other post responses.

You can do the same method with alloy floor as i mentioned with the Ply board.

Cut out access panels in alloy flooring with angle grinder or pneumatic grinder with cutting wheel, do what you need to do under flooring through access panels openings then go out & buy some alloy sheets same thickness as origional flooring, measure & cut to size & lay over the top of origional flooring in cockpit & pop rivet or maybe you can use some self tapping screws to hold it all down. You can make cutouts for seat tracks & other floor fittings that may be their & re-seal once all done. The aviation sealant is manafactured by Semkit & they may sell it online.

If you do this method try not to cut through any floor beams as they will be needed to hold up all the flooring in cockpit & offer structual strenghtning.

Once complete you can maybe paint the alloy flooring flat black or use some wing grip tape or paint to apply non slip flooring.

I recogn it would come up like a treat if you go with this method in the end. Would love to be their to give you a hand.

If you need anymore assistance feel free to ask.

Chock Chucker :ok:

[Alber Ratman]

Attack the screws with a rattler and scrape out the sealant with whatever..:)

[NutLoose]

Do the screws up a bit first, it will break the sealant hopefully and if it rounds the head slightly it will not matter as you use the other side of it to undo them.

[Fooman]

Good Morning all.
Just thought I'd let you all know that the least destructive method of a heatgun worked. (Best $34.95 i've spent in years). When I say least, it did cause slight deformity on the larger panel edges as they expanded. I did also learn another valuable lesson. When you think the things you are about to touch have cooled down enough to actually touch, go inside and get a drink for a few minutes. Don't ask how I know, but you'll figure it out.

Hey Chock Chucker, where in Australia are you located? As for your suggestion of panelling over the top, I think I'l do that as there are lumps and bumps everywhere.

Again, Thanks guys.
Rob.

[Chock Chucker]

Good on ya Rob,

Sounds like you had fun along with a few burnt fingers.

I live in Adelaide. No worrries yeah i recogn if you go out & buy some aluminium sheeting same thickness as old cockpit flooring & then cut to size you can cover all the cockpit flooring & make it look all sweet & brand new.

Once the cockpit flooring is cut to size you can pop rivit it in place over the top of old flooring or use some self tapping screws to hold it all down & in place. Just what ever you use to hold flooring in place (pop rivets or self tapper screws) make sure they dont sit to proud or they may be a trip & slip hazard to all using your flight sim.

You could even use 2-3 inch velcro strips with self adhesive backing to hold down new ally sheeting on to the old cockpit flooring & then seal the edges with sealant. You can buy velcro in BigW, Kmart in knitting/sewing aisle or at sewing shops & even hardwares.

You may want to apply a thin coating of some type of glue, silicon or sealant between old flooring & new flooring before pop riviting or self tapping screws. If not it may make funny sounds when walking on it. You can test this out before you bolt the new floor down.

Once its all in place then you can paint the new floor say flat black if that was the origional colour or you can also get wide rolls of black colour wing grip tape (non slip tape) that has an self adhesive backing on it to apply over the whole floor. The company that makes this wing grip tape is 3M.

I belive you can also buy wing grip paint that you can use to paint the floor with. Its like sand or grit mixed in with paint to give it the non slip function. 3M may have this also or boating shops as its also used for the upper deck on boats/yatchs for non slip.

Your local Bunnings hardware may be able to supply you with aluminium sheeting & the wing grip tape or paint if you choose to go this way.

If Bunnings dont have then you live in Melbourne correct ? then you can make a trip out to Morrabbin General Aviation airport & Knock on some GA maintenance hangar doors. They may be willing to sell you the correct aviation grade aluminium sheeting, wing grip tape, wing grip paint, velcro strips, flat back spray paint & semkit sealant if you want to seal between the old & new flooring & the edges of the new flooring.

The Semkit aviation sealant is a 2 part mix so if you dont know how to mix then see if the guys at the GA hangar that provided you with it can give you a demo on how to do. Best way to spread the sealant thinly is with a thick paddle pop stick & use the long edges to stroke it on.

If you need anything else the GA companies at Morrabbin airport would most probably be able to help you out & sell you items, such as cockpit decals, life jackets etc etc ..... The GA airports normally have a pilots book shop which sell a lot of stuff related to aircraft, pilots & aircraft engineers both in study books & so on & some aircraft accessories also.

Maybe even check the net to see if you can find any coumpanies that sell what you need also.

All the best & if you need any more assistance then please dont hesitate to ask.

Would love to be their working with you & giving you a hand. Sound like fun & i'm sure it will look great once you have it all done. Maybe you would be willing to post a photo of your flight sim on this forum once complete for all hear to see.

Chock Chucker :ok: