Stuck screw

[huruta]

We are trying to get our outboard motor off our seawisw Davit to service it. It is bolted to the frame and one of the screws won’t come out. We sprayed mclube sailkote and still no movement. Looks like has white film near juncture(salt build up)? How can we get it to loosen? If a different lube, how long will it take? Thank you!

 

[ranger58sb]

We've sometimes had OK luck with Kroil and with PB Blaster. Days... or more...

-Chris

 

[Comodave]

And heat.

 

[STB]

Kroil is my favorite of the penetrating oils, hands down. Spraying it at the problem to saturation every few hours for a small few days or soaking the part, or otherwise saturating the area and let it creep its way into the ceased interface works almost always for me.

When it doesn't work, I add heat, often times a lot of it, via a torch. That almost always takes care of the stubborn ones.

When I've gotten into real trouble, I've taken parts to a local machine shop. They heat them until they glow red and then melt a simple drug store candle into them. The parts seem to just spin apart from there. They tell me that they have been using cheap candles for years and that they work better than penetrating oils.

I've tried the candle approach, myself, with less luck. In one case, I eventually got the parts apart to learn that the candle wax had a fairly shallow penetration. I'm not sure what I did wrong. But, I suspect that I didn't get it nearly as hot as they did.

I'm thinking it was the high heat that allowed the wax to be drawn in and work.

Hope this helps.

 

[huruta]

Thank you! Will give Kroil a shot.

 

[Portage_Bay]

The white film is probably big trouble. If one of the metals is stainless and the other is aluminum they will be a real challenge to get apart.

Kroil is probably the best penetrating oil. Heat will work but you need to understand how to apply it to get the 'hole' to expand and the screw or bolt to stay the same.

Of interest to you might be a Project Farm Youtube video on penetrating oils. If I remember correctly he also tries the candle wax approach.

What I have found that will work sometimes is patience. Lots and lots of patience. The penetrating oil of your choice. Maybe heat. Maybe heat and wax. Then just the right amount of force to get it to move. I can't possibly define just the right amount of force. As soon as it move at all move it back the other way. Add more penetrating oil. Keep at it. A little this way, a little that way. Patience. Gradually you will get more movement.

Sometimes it helps to start by trying to tighten it a tiny bit. Counter intuitive as that seems sometimes it works.

Good luck. If the corrosion is deep enough in the screw it will sheer off. If you force it too hard it will sheer off.

This is one of those things that experience really pays off. You're about to get some experience.

 

[huruta]

Portage bay, Good to know. Recently ditched Seattle for Bellingham but boat still in Seattle. A day project that may turn into, who knows what?! May need to tend it when we head out for the weekend. Thanks to you and STB for your insights. Kroil is now on and hopefully starting to work it’s magic.

 

[jgwinks]

Sometimes, depending on how the parts are bolted together and do I need to keep all the parts, I will just keep turning the bolt until the head snaps off. Remarkably easy to do, often they just snap and you don't have a choice.

 

[mvweebles]

Can you get an impact hammer on it? Maybe whack a wrench with a hammer? Serious vibration definitely helps

I hate when this happens. Good luck

Peter

 

[PM]

An air impact hammer will loosen the toughest nuts, bolts and screws. Get a good fit on the head.

pete

 

[STB]

To make a serious attempt with the penetrating oil keep adding it to keep it wet and give it time, even days, to seep in and work. It isnt one of those things where a dab will do it. Time and soaking or saturating are your friends.

 

[RT Firefly]

Greetings,
Mr. h. Whilst I am an enthusiastic proponent of the application of heat, keep in mind that too much heat can melt alloys (outboard motor flanges/blocks etc.). It's the Goldilocks approach. Not too much,not too little but just right. The just right part takes some experience.

Soak, soak, soak and be patient.

 

[Comodave]

To make a serious attempt with the penetrating oil keep adding it to keep it wet and give it time, even days, to seep in and work. It isnt one of those things where a dab will do it. Time and soaking or saturating are your friends.

Also tapping with a hammer to create vibrations to help the lubricant work its way into the threads.

 

[plittle2005]

All you need:
https://www.harborfreight.com/heavy-duty-impact-screwdriver-kit-9-piece-58151.html

 

[Nick F]

I recently had a very experienced machinist remove some stuck bolts for me (Stainless in aluminum). He used an impact driver (that you hit with a hammer) and it loosened bolts that I knew I would break by applying steady force.

Klein Tools 70220 Reversible Impact-Driver Set (for instance)

 

[CharlieO.]

What Phil and Nick said (sorry if I missed anyone else), that is my go-to tool for stubborn screws. I've even had success getting previously stripped head screws out.

 

[mike66]

I've had luck using CRC Freeze Off after trying heat. I tried to spray the bolt to make it shrink a bit. Worked when heat and penetrating oils didn't. Took almost the whole can but it was worth it.

 

[Datenight]

What Phil and Nick said (sorry if I missed anyone else), that is my go-to tool for stubborn screws. I've even had success getting previously stripped head screws out.

You all beat me to it! I keep one in the truck.

Rob

 

[Mischief Managed]

I've had luck using CRC Freeze Off after trying heat. I tried to spray the bolt to make it shrink a bit. Worked when heat and penetrating oils didn't. Took almost the whole can but it was worth it.

THIS! I keep a couple of cans of computer keyboard duster (Walmart sells it) and a MAP gas torch on my boat for this purpose. If you turn the duster can upside down it makes incredibly effective freeze spray. I get the whole area and fastener hot with a MAP gas torch, blast just the fastener with freeze spray and then back the fastener out. Works really well.



The freeze spray method is great for pressed on/interference fit parts too. A few months ago I had to install a harmonic balancer and the service manual explicitly said not to use the bolt for installation and to use a very expensive special tool instead (that I don't own). I popped the balancer in the oven at 180 F for awhile, and just before I installed it, I blasted the crank snout with a whole can of freeze spray. The balancer slid right on with no tools required. I let it cool and torqued it to spec.

 

[huruta]

So, we were able to get some work done! We used Kroil and let it sit for a few hours and were able to get the bottom screws off and drain and replace the gear box oil (yamaha 15hp 2-stroke outboard). We were not able to get the screw that attaches said outboard to the Seawise Davit loose so we had to do the work with the engine on the outboard using two hands, paint drop cloth and multiple oil capture tools successfully. I suspect that given more time and kroil and perhaps some other great suggestions here, it will loosen and for next year's service we can get it off. Also replaced the gas (which was from a car gas station and had ethanol in it) with marine grade gas and added oil and stabilizer. Took it for a spin with no issues - whoop!

I am always amazed at how seemingly simple service/repair tasks are never that simple - at least to us who are not particularly handy. And it's never what one expects to go wrong and we never seem to have the right tools. With the purchase a few tools, we also changed the spark plugs (bought a socket kit with 30+ sockets but none worked so had to go get a different size), put up the upper deck bimini (didn't realize we needed to move the frame, or how to actually do that until a visit to a marine bimini maker who gave us the tool), and got a number of other housekeeping items checked off our list.

Probably letting our rookie status known, but I so appreciate this forum and all the expertise you share - THANK YOU for helping out!

 

[djones44]

[QUOTE
I am always amazed at how seemingly simple service/repair tasks are never that simple - at least to us who are not particularly handy. And it's never what one expects to go wrong and we never seem to have the right tools. [/QUOTE]

I am now dealing with a seized spin-on oil filter with the same issues. I haven't used the Suzie generator much at all, with maybe 5 hours, but after 5 years..

It involves inverted boat yoga, one hand only, maybe 1/4 turn. After three different oil wrenches I realize that it's fused. Now I have to figure what those weird nuts are defending the filter mount assembly. It gets lonely...

 

[RT Firefly]

Greetings,
Mr. h. EVERYONE is a rookie at some point and in some situations. No worries. A learning experience.

 

[Comodave]

[QUOTE
I am always amazed at how seemingly simple service/repair tasks are never that simple - at least to us who are not particularly handy. And it's never what one expects to go wrong and we never seem to have the right tools.

I am now dealing with a seized spin-on oil filter with the same issues. I haven't used the Suzie generator much at all, with maybe 5 hours, but after 5 years..

It involves inverted boat yoga, one hand only, maybe 1/4 turn. After three different oil wrenches I realize that it's fused. Now I have to figure what those weird nuts are defending the filter mount assembly. It gets lonely...[/QUOTE]

I just changed the engine coolant in my engines. Also did the coolant filters, but just barely. I tried a filter wrench, then put PSA sand paper on the filter and filter wrench, no go. Bought a new strap wrench and it started to deform the filters so I went back the the filter wrench and they finally came loose. Of course access was part of problem on the port engine filter. Finally took off the aftercooler and that got me close enough to get it off. Took an hour for each filter…

 

[BruceK]

One way to remove a spin on oil filter is drive a screwdriver through and through, and use it as a lever. Whether that overcomes "fused" threads I know not.

 

[Comodave]

I thought about that but what if they still won’t come off? Then I am stuck with an engine(s) that I couldn’t run. Worst case I could have left the old filters in place.

 

[plittle2005]

To avoid a "fused" spin-on, always put a film of oil on the face-sealing square O-ring seal. Rubber seals typically "micro-deform" into the surface roughness of the sealing surface, and if installed dry will offer great frictional resistance!

PO did not lube my fuel filter spin-on, took a lot of incantations and deformation to get it off. For my next change, lubed, came right off!

 

[porman]

I've had a couple filters seize on Porsche 944's, where the filter sits upside down at the top of the engine. Great design. After the filter housing is destroyed beyond recognition I ended up using an air hammer and chisel to break the mounting plate and threads loose. At least it's accessible, upside down, on top, where all the oil drains down the side of the engine. Did I say great design?

 

[jagates10]

This thread screams the need for a "like" button or maybe one that says "Been there, done that, got the tee shirt" button. Seems like removing filters is always reminiscent of "the sound of one hand clapping"!

 

[Action]

^^^^ +1

Does anti-sieze have a benefit for marine applications?
I use anti-sieze a lot more on newer automotive applications because of the disimilar metals auto manufacturers are now using. Especially with the use of alloy materials.

Anti-sieze has helped me a lot with spark plug removal in alloy cylinder heads. Messing up the threads in a cylinder head is the start of a bad day, err week.

 

[Comodave]

I use Tef Gel.