Corroded bolt

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Snoopy11

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While changing thermostat on my Honda BF75A we encountered a bolt that wouldn't turn due to intense corrosion -- bolt frozen (not cold) in place. Tried CRC and WD40 with no success. Found others on the housing T-stat attached with similar issue. Bolts don't appear to be strong enough to handle much torque. Any ideas / suggestions to removing them and corrosion that is deep inside?
 

gm280

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Other then some good penetrating oils and maybe a little heat, just work it back and forth until you either get it out or break it off. If you break it off then comes the drill and such thing to remove the threaded section. I hope it is an area that you could actually get a drill into. JMHO
 

Sea Rider

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If rock stuck, severely seized on thread, worst if salted, penetrating oil, W40 won't do their homework, seems inevitably that will break when trying to be removed. Drilling is your worst nightmare...good luck

Happy Boating
 

StarTed

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An old stand-by is 50/50 acetone and automatic transmission fluid and lots of time. Alternate heating and cooling tends to cause stresses between the bolt and housing and may aid in separating the threads.

If drilling the bolt start with a small short drill and keep it centered as well as possible. It will drop when exiting the bolt. Don't drill any further. At that point I use the acetone and ATF soaking from both sides. It may take a week or two if you can wait. That's worked quite well for me saving the threads in the housing.

Good luck.
 

robert graham

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CRC Freeze-Off uses very cold blast to possibly shrink/loosen a stuck fastener....maybe alternate the cold with a heat gun to shock those bolts loose...Walmart carries Freeze-Off......
 

Snoopy11

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CRC Freeze-Off uses very cold blast to possibly shrink/loosen a stuck fastener....maybe alternate the cold with a heat gun to shock those bolts loose...Walmart carries Freeze-Off......

Thanks Robert. I have used CRC before but hadnt heard of freeze off. Sounds like a possible solution. Someone mentioned to try
Corrosion-X. Its suppose to be many times stronger than WD40 and apparrently the Navys "go to" chemical for corrosion. Has anyone had success with it or have feedback about its use?
 

gm280

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First of all, WD40 is not a penetrating type lube. It is a "Water Displacing" lube. So it is doing virtually nothing in this situation. WD40 is great for a lot of things, but not loosing corroded bolts and nuts. Heat and cold are good ideas as well a taping on the head of the bolt with a small hammer to shock the corrosion. Keep applying the true penetrating oils (liquid wrench, PB Blaster, Kano Kroil, etc.) and work with it before doing anything drastic.I personally like Liquid Wrench. It is like water and therefore creeps into the threads and such. I can tell you working a few days is well worth the effort then drilling it out. JMHO
 

mjf55

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Having just broke and drilled out 2 bolts, its not fun but not particularly hard.
First, follow gm280's advice above. For heat, I got a mapp torch and it works great.
If / when a bolt does break, use some kind of a center punch to dimple the CENTER of the broken bolt. ( If you go off center, it is much more messy, and dont ask me how I know). Use small drill bits to start and work your way larger. I use Cobalt drills and go slowly and use oil to lube the bit.

Retapping will be required.
 

Snoopy11

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Thanks for sharing experiences and offerring advice. Will try techniques mentioned in posts and advise on results.
 

Sea Rider

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Asume thermostat and housing T-stat has not been removed, right ? If so what's stuck, extremely seized up is lower bolt's thread onto t-housing stat threads., won't be possible for any product to reach and penetrate that area. In that case heat will need to be applied on stat housing exterior threads area for bolt's lower threads to help become loose, if that's possible.

If not, remove bolts with wrench and expect to break some, if that happens follow broken bolts removal procedures as suggested,

Happy Boating
 

Snoopy11

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Asume thermostat and housing T-stat has not been removed, right ? If so what's stuck, extremely seized up is lower bolt's thread onto t-housing stat threads., won't be possible for any product to reach and penetrate that area. In that case heat will need to be applied on stat housing exterior threads area for bolt's lower threads to help become loose, if that's possible.

If not, remove bolts with wrench and expect to break some, if that happens follow broken bolts removal procedures as suggested,

Happy Boating

Thanks Sea Rider. Changed T-stat successfully. That's working so solved one issue but along the way created a 2nd. Top bolt broke when we tried to remove it. Tried removing it with TLC but it was really frozen deep in the threads. Broke inside the piece the T-stat cover is attached too (name?).

Before I try broken bolt removal process mentioned previously, a question: has anyone had experience using an heli coil set to remove a broken bolt on an OB? It works for our aircraft engines, thinking it should work for the OB....
Appreciate feedback.
 

Baylinerchuck

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I've used heli-coil thread inserts to replace stripped out threads. One common use of heli-coils is Spark plug threads. Never used one to remove a bolt, unless we are talking two different things, I.e., EZ-out.

As far as penetrating oils go, my grandfather used brake fluid to loosen rusted threads. I've tried it myself and it works well so long as it sits overnight.
 

cwburkeva

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Have you used PB Blaster? Spray every few hours and soak at least 24. Also apply a bit of heat, if it isn't close to anything flammable or would damage surrounding areas.
 

gm280

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Snoopy11, if you are use to removing broken bolts in aircraft engines or frames, then you basically do the same procedure with your OB as well. However, and I am certain you already know this, don't break off the Eze-Out while trying to remove the broken bolt. Those Eze-Outs are made of some very hard metals but are equally near impossible to drill out. If you get to a point that you think the Eze-Out will break before spinning the bolt out, stop and go the progressive drill out routine. It is a lot easier then trying to get a broken Eze-Out out of the bolt. JMHO
 

Sea Rider

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Is there some lower bolt portion peeping out hole say some milimeters out or bolt is broken flat even at base ?, can you post a picture of the issue ?

Happy Boating
 

hemi rt

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When drilling out a broken bolt try and use left handed drill bits. I have broken bolts actually come out using these bits, the drill bit seems to warm up the bolt while drilling and in each case the bit grabbed to stud and turned it out.
 

Snoopy11

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Have you used PB Blaster? Spray every few hours and soak at least 24. Also apply a bit of heat, if it isn't close to anything flammable or would damage surrounding areas.

Yes, tried sea foam and Corrosion-X -- non of these chemicals or sister chemicals are available in my location. Need to order from the States.
Bolt in lower section so hard for chemicals to penetrate.
 

Snoopy11

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When drilling out a broken bolt try and use left handed drill bits. I have broken bolts actually come out using these bits, the drill bit seems to warm up the bolt while drilling and in each case the bit grabbed to stud and turned it out.

Interesting idea, have not thought about uding a lefy handed bit. Thanks!
 

Snoopy11

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Snoopy11, if you are use to removing broken bolts in aircraft engines or frames, then you basically do the same procedure with your OB as well. However, and I am certain you already know this, don't break off the Eze-Out while trying to remove the broken bolt. Those Eze-Outs are made of some very hard metals but are equally near impossible to drill out. If you get to a point that you think the Eze-Out will break before spinning the bolt out, stop and go the progressive drill out routine. It is a lot easier then trying to get a broken Eze-Out out of the bolt. JMHO

Not use to it but done it once or twice with an A&P. Thanks for the advice and good point on Eze-out ...
 

Snoopy11

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Is there some lower bolt portion peeping out hole say some milimeters out or bolt is broken flat even at base ?, can you post a picture of the issue ?

Happy Boating

Will send pic Sea Rider depending on my internet speed. Its soooo slow here....
 
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