Removing Sikaflex

[George.]

Is there any substance that will dissolve or soften Sikaflex without destroying wood and metal?

I am trying to remove Dalia's windlass for maintenance. I got off the bolts that separate the deck plate from the gearbox under the deck. Both should have come loose. Instead, nothing happened. The Sikaflex that I used to bed the deckplate when I assembled it 3 1/2 years ago seems to have bonded them tight and fast to each other. redface.gif

Pounding with a rubber mallet had no effect. Trying to cut them loose with a thin blade didn't work - the deck plate is too tight against the deck, and due to the proximity of the bowsprit and forehatch, there is no room to do it.

If nothing else works I'll have to go at it with a chisel, destroying the deck planks around it, and later having to fix the mess - which I would like to avoid if at all possible.

Aby suggestions?

[David McCollum]

I have read that a hot putty knife can soften the adhesive. I have never tried it myself, but the suggested procedure is to repeatedly heat the knife with a torch and work it between the two parts.

[JimConlin]

Children, let this be a lesson to you!

[kpenokie]

There are products that claim to loosen the bond between the goop (silicone whatever) and the surface. You can get them them at most hardware stores and home centers. I used some on a screen door casing and it worked adequately.

[ 09-08-2005, 01:13 PM: Message edited by: kpenokie ]

[outofthenorm]

You might be able to use a very fine wire (like a guitar string) to cut the Sika. Use a couple of short dowels as handles and the wire will work like a fine saw.

Good luck!

Norm

[Matt Cohen]

There's a product called DeBond... claims to remove 5200. So it must be able to free up sikaflex.

[George.]

Originally posted by JimConlin:
Children, let this be a lesson to you!A lesson indeed. And the worst thing is that when I go to put it back on (assuming I ever get it off), the instructions quite clearly say it should be set with plenty of bedding compound. :confused: :mad:

Thanks for the advice, you all, but remember, I am in small town Brasil - no US brand names, no well-stocked hardware stores. I need to find a basic product that will do the trick, like kerosene, acetone, paint thinner, whatever - or at least the active ingredient of some brand name product, so I can look for its local equivalent.

[Tom Lathrop]

If I had the problem you describe, I'd rig a hot steel wire and drag it between the two stuck pieces. Getting the right amount of electrical current through the wire to make it hot, but not too hot to penetrate the caulk is the issue but an electric light dimmer might do that. Batteries of the necessary voltage would be safer

I won't describe it any further since I don't want to be responsible for any misinterpretations or accidents.

[George.]

Originally posted by Tom Lathrop:
I won't describe it any further since I don't want to be responsible for any misinterpretations or accidents.:D

Actually, I am sitting here thinking whether 24 volts (i.e., two batteries rigged in series) would be enough. Or whether I could stand any more voltage on my hands as I do it...

[sdowney717]

Have you tried twisting it?
Put some leverage on it to twist it off.
It may tear the sikaflex free.
Or is there a way to disasemble it leaving the base plate on the deck. Then heat the metal lightly with a torch to free it.

[George.]

Twisting was my original idea - but it won't twist until I take off the gearcase from under the deck, as there are four fixed bolts between gearcase and deckplate.

Heating the deckplate sounds promising, though - I already took the windlass apart, the only thing left on the deck is the deckplate. Will try tomorrow.

[dmede]

Originally posted by George.:
[QB]]A lesson indeed. And the worst thing is that when I go to put it back on (assuming I ever get it off), the instructions quite clearly say it should be set with plenty of bedding compound. :confused: :mad:
well thats partialy the problem, stuff like 5200 and some of the sika products are not bedding compounds at all but flexible adhesives.

if its the sika 291 then it is an adhesive. they have others that are weaker and can be used as bedding.

dave

[Tom Lathrop]

Originally posted by George.:
</font><blockquote>quote:</font><hr />Originally posted by Tom Lathrop:
I won't describe it any further since I don't want to be responsible for any misinterpretations or accidents.:D

Actually, I am sitting here thinking whether 24 volts (i.e., two batteries rigged in series) would be enough. Or whether I could stand any more voltage on my hands as I do it...</font>[/QUOTE]I expect that 24V is way too much although it depends on the resistance of the wire. Remember that this is a short circuit. I do know that heat will soften and release 5200 so heating the base plate is a good thing to try. As was suggested, next time don't use 5200 as a bedding compound.

[JormaS]

If you happen to own a Fein Multimaster, and the thin putty knife type blade that comes as an accessory, then you could cut the bond at least 2 or 3 inches inward from the edge of the deck plate. After that you might be able to twist the fitting. If not, I would bet on the wire method. DeBond would not work because you can´t get it in there.

[paladin]

Using steel hair wire and 12 volts will make a sudden hot wire fuse and take maybe 3-6 seconds to glow cherry red and evaporate.....a couple of "D" flashlight batteries in parallel might make it....dunno burn yourself....

[Scott Rosen]

Try the wire method, but without the heat.

And don't ever use a PU adhesive for bedding a fitting that you will one day want to remove. If you must, then use a release agent before you bed.

The oil-based bedding compounds really are great. Even if they dry out after five or ten years, it's easy to remove the fitting, clean the surfaces and rebed.

[ 09-08-2005, 05:56 PM: Message edited by: Scott Rosen ]

[carioca1232001]

George,
Contact your local borracheiro and ask him to lend you his electrically-heated faca . It is part of the standard kit of any borracheiro worth his borracha ( or salt ?).
With faca plugged into the mains and a little help from able hands, go about taking this Sikaflex-set piece off wherever it was installed. ;)

[MRJarret]

George,

I had a similar situation with Phenoseal... ended up calling their tech assistance phone number and got some great help. Can you chase down (on the catridge or online) the phone # for similar Sikaflex help?
MRJ

[Bob Cleek]

There should be another "FAQ" called "I told ya so's." Not to make light of your misery, but there are a lot of people posting in here who get testy when they are disagreed with. This post would shut up maybe a quarter of them!

[JormaS]

After alcohol, Sikaflex is the most widely misused stuff in boats. But we have all sinned...! ;)

[Gerald]

George
I bought a wood burning setup that consists of a rheostat and a common wire that you shape and replace as required. At the highest setting the wire is damn hot. I haven't tried putting a longer wire in the unit but it would surly heat a longer wire. I have seen the same wood burning setup in several cites.
Gerald

[werner]

the wire method (guitare string or..) with a handle on each end is also used to "saw" out the glass "windscreen" imbedded in PU cars.It works quite fast.

[shamus]

Try hauling the anchor with the bolts out. smile.gif

[imported_Jimmy]

When you put it back on, use a bedding compound like dolphinite, or if you can't get that, plumber's putty should work. Do a search on bedding compounds.

[George.]

Thanks for all the responses. I actually went out to the boat to give the wire method a try, but it didn't work out, for two reasons:

1) I screwed the darned windlass so nice and tight against the deck that not even a hair will fit between wood and bronze - let alone a steel wire. I realized that what I'll have to do is dig a groove with a chisel all around the windlass in order to get the wire in, and once I re-install, fill it with a NON-ADHESIVE putty. ;) redface.gif :D

Since I am soon leaving on a long trip, that'll have to wait 'till I come back.

2) As I stood on the foredeck looking at the darned thing and scratching my head, a 20 knot wind blew in. A sailboat passed in the distance. Too much temptation. I called Sil, she drove to the marina with Lua and Estrela, we cast off, set working sail plus jib topsail, and had a great two-hour sneak sail, beating at 7 knots, broad-reaching back at 9... smile.gif

[Gerald]

Lua and Estrela
Cool names! They just have to be from the same family.
Gerald

[George.]

I was going to post a classic photo of Lua and Estrela - but I just found out that friggin' Imagestation now wants money! As if it was not bad enough to have to delete their spam! :mad: :rolleyes: tongue.gif :D

[werner]

George perhaps this will work??
if there is a possibilty to drill a small hole in the middle - tap thread for a grease fitting -fill a grease gun with oil or grease------> do not know what will give put something will ; it gives tremendous pressure
this is a good method of freeing stuck brake pistons so perhaps it also will work in this case??
Anyway whatever you do NEVER NEVER use air pressure!!!!

[JormaS]

By now we may have concluded that some damage to the deck must be accepted. The next step would be to apply heat to the metal plate with a blow torch (to soften the bedding compund), and start driving in wedges under the plate. In the end, something will give. If it can be done slowly...maybe during several days...and with a lot of heat, the damage to the deck could be minimal.

[merlinron]

i am i new guy here on the firum, but have a great deal of woodworking and mechanical experience. if i may make a suggestion....
if there is a place diectly below deck of the windlass, where you can get a small 1/4 inch thick steel plate to rest on a floor timber, keel or stem ( even if you have to chisel a small level step in the keel or stem) you can have someone hold a piece of iron pipe just long enough so that it's upper end is just under the deck somewhere at the outer edge of the deck plate, with another small plate as a cap. above deck at the plate, drill a hole the correct size for a 1/2 inch coarse thread tap through the deck plate and deck and then tap the hole. now run a 1/2 inch bolt down to make contact with the pipe and plate below, making sure you have several threads let above the deck plate, and jack screw the plate loose. i doubt if any adhesive will resist this method. afterwards, obtain a 1/4 inch brass or bronze pipe plug and turn that into the threaded hole to plug it, the threads should match up good enough to allow the plug to tighten nicely.

[Paul Scheuer]

Some time ago I glued several brass pieces to my mahogany sheerstrakes with 5200. The idea was that I didn't want a bunch of fastener holes. Once they were on, and hearing all the warnings here, I'll never want to get them off anyway. After five or six thermal cycles here in Illinois, they popped off easily. I'll vote for chilling the plate. Maybe with dry ice. It seems like there would be less chance of damaging the wood.

[Gary E]

George,

Here is a way to exert a separating force between the deck and the metal flange.

Sounds to me as though what you have here is not unlike a very good glue job, and that glue is holding the flange in tension. Here is what I would try.

If driving putty knifes under the flange does not do it the following may help.

First is there a spot is several places above the glue joint where you could drill a hole and stop just at the deck/flange joint? If Yes, read on if No, then stop reading.

Get 8 bolts aprox 8 mm or 10mm with the finest thread you can, is that 1 or 1.5 threads? (my metric skills here are lacking) with the thread length longer than the flange thickness and a set of taps to suit... we call the starter tap PLUG, and a BOTTOM tap. Drill for the tapped holes in the flange using the proper drill diameter, you are going to thread these holes using the tap set. STOP drilling at the wood deck. Now using the tap set tap the flange, finish up using the bottoming tap to get as close to the deck/flange joint as posssible.

Next you need as many wide putty knifes as you have tapped bolt holes and drive them parallel to the deck under the flange and past the holes you tapped. Next you install the bolts, they will screw down to the putty knife and at then you start cranking on each bolt 1/4 turn at a time on each untill the seperating tension overcomes the glue and the flange is free.

[Gerald]

What werner said!
Gerald