read article in 'Good Old Boat'
Great reading in GOB nov/dec. issue. What to use where, why, and how come!
Worth the price of the mag.
bedding handrails and coamings
g'mornin Graig,
Butyl doesn't adhese too good. It is a rubber bedding material classed as a sealant. It's major contribution to the caulking wars is that it remains flexible, which is where waterproofing comes in. The 'sheet' stuff or sticky tapes you get from auto stores are recomended by New Found Metals, eg, for mounting the inner parts of their ports. The stuff is black so they run a cosmetic bead of something white around the squeezeout areas (Sikaflex 291). S291 is a fast set polyurethane.
I think it is agreed that polyurethanes and even polysulfides loose flexibility over time from UV and boat lotions. So here is where your super adhesive gets leaky. I don't know that I would use tube butyl (comes in colors and white) to bed rails on the cabin. I might try the tapes if they came in white, because you want a 'caulk line' On the rails I wouldn't want to squeeze out any caulk or adhesive I put there.
Might try the approved stanchion base method on the rails which is to spread an even thick layer (GOOD LUCK!) of caulk, mount in place and then semi-cinch the fastenings so that everything is even and positiuoned, let it harden to some degree (some will say partially - others will say all the way) then drive the screrws home, hopefully pulling the rails down so that the caulking bulges. (Sheet or sticky gasket material would be SO much easier.) You will have done some carefull blue taping. Last resort would be to cut the bulge off when you leave the tape on too long. Could look real smart!
If you decide to use tube butyl to mount the rails because of its reputation to always flex, here is a trick I just read about. That is to use O-rings around the fastening holes to avoid squeezing all the sealant out. For that matter, if I had some of the tape which is much more firm than butyl out of the tube, might try doughnuts of that around the screw holes. And finish up with tube butyl or polysulfide.
Might go with 4200 - but polysulfide has a rep for lasting longer exposed, and renewing is 100 times easier.
There are issues mounting the hand rails to the cabin. My guess is that witout elaborate oversized drilling and filling the cabin/liner the rails will always want to move. Injecting epoxygel inside the cabin/liner can't be taken lightly, as that can be even more permanent than 5200! The liner is dimpled and distorted by the screws so you have to decide what level of restoration you want.
For a quick fix I would use polysulfide.
I always think in terms of having to take things apart later, curse of the maintenance man. I think dissimilar materials should be bedded, but that's just me - somebody else wants to glue them together, that's ok too! But I'ld have to be starving to take the job of fixing the leak that is bound to show up.
NFM recommends using a metal spatula heated with a hot air gun to soften 5200 when you're trying to remove it! :D
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Butyl - which is so cheap - might also be considered to bed the coamings. It would be great if an inexpensive material could be useful on the boat. Cleanup is with not so bloody lethal mineral spirits. Hope someone trys it here and reports. :cool:
POLYDIMETHYLSILOXANE OIL removal
Silicone keeps cropping up. This is a great thread to bone up on the subject - look at at craig's post here (c.amos)
One the great miscarriages of justice is that silicone is still allowed to be used on fiberglass boats. (Talking 'bout corporation ethics) But silicone removal is a problem in all spheres. It looks like the makers of the material are also coming up with the removers - which seems logical enough. I've just come off reading some DIY forums and there are folks out there who are criminally stupid. So watch it if you are trying to find information on how to clean the cabinsides where you are rebedding OR where your new windows are going.
Remove excresil by cutting it off (nope, this is not easy either) and then use a sharp pull-type scraper. Don't abrade the surface yet with sand paper. The grit will create tiny valleys where you have driven the silicon oil. Don't use any solvent like acetone. Solvents drive the oil residue into the frp laminate. Don't use a torch or heat gun on it - for the same reason. This is the last thing you want to happen.
There are silicone digesters and waterborne strippers appearing on the market. Some sound very aggressive. You might find these at an autopainting supply store. These strippers/paint preps are formulated for the trade - they may be too much for a more porus surface like fiberglass. This is our problem. I figure I can mechanically remove the rubber by cussing and scraping. But to remove the oil so that the next generation of goop will stick properly we need one that will not just drive the oil or attack the gel coat and polyester or other plastics used around the boat.
After you've successfully gotten the oil out of the gel coat then sanding prep can proceed.
Here's a silicone remover that is said to be safe on plastics and fiberglass. I have NOT used this stuff YET nor have I read any knowledgable forum-type comments on its use:
DOW CORNING OS-2 SILICONE REMOVER.
You can get a bottle from McMaster Carr for $10.23 - 10oz aerosol. (8460T3)
I have ordered some. I'll wipe the area down where silicone probably was and dab some epoxy gel on some spots where the new window gasket is going and see if it bonds. If the epoxy chips off, I'll still have a BIG problema.
Said to be an aqueous solution - said to be relatively benign is far as skin and VOCs goes. Like I say, there is no literature I can find on its practical use. Said to remove silicone oil and grease. Whether it will deep clean gelcoat fiberglass ....that is something
somebody will hopefully be kind enough to report back here to us.:cool:
Wist Marine sells polyurethanes and they have a 'debonder' for some, might not work on polyethers. They sell no remover for the polysulfides.
They also sell a couple brands of silly con but offer no deoiler for them. Their Wist Advisor doesn't admit to this very real oil problem which is obviously endemic and has been around for many Catalogs. And must be the cause of untold failures and frustration at repairing leaks.
'If we don't have it you don't need it.':(
not a plug for another silicone oil remover maybe
FYI
Micro Care Corp 'VeriClean'
Electronics grade flammable methyl siloxane (VMS) solvent.
Removes rosins, fluxes, organic residue, ionic deposits, light grease, fingerprints. (Anybody assembling their Ham Radio kit?)
"Silicones are found in many lubricants, adhesives, conformal coatings - VeriClean removes them all...particularly effective when the coating was fully cured.
"Cleans up silicone residues from other manufacturing processes....100% votilile, cleans without need for rinsing."
"Safe on all common components, gaskets, elastomers, insulators, cables, connectors...can be used on plastics, metal, paint, glass, fiberglass....skin contact. Low odor." Can you really take a bath in it?
Datasheet avoids mention of breathing it - eyes.
Produced from quartz. (How they do that? Is it ok to ask how methyl siloxane is extracted from quartz? THOSE processes are not on the label or data sheet.)
"Degrades quickly in the atmosphere (less than 3 weeks)." THREE WEEKS!!!:eek:
"Ozone safe, including propellant - very low GWP (Global Warming Potential.)" Dow Corning. $15 aerosol, ground shipping ok.
Found it at HMC Electronics
www.hmcelectronics.com
Wouldn't surprise me at all if the stuff from McMasterCarr and this stuff is exactly the same stuff packaged in a different can, more expensive. Personally, in my opinion, Dow can't make a safe product. Not in their nature.
another silicone and adhesive remover
nope haven't tried it.
DSR-5, seems to be mostly aliphatic hydrocarbons and special wetting agents. They call it an "un-bonder"
You work it in where you want to remove CURED SILICONE AND 5200.
Said to be "safer than most solvents regarding skin contact and material." Non-corrisive. Non HAZ MAT.
Safe on metals, aluminum, glass, wood, cabinets, fiberglass, gelcoat, acrylic, polycarbonates, carpets ,vinyl flooring and fabrics, varnished, urethaned or painted surfaces, formica.
Removes other adhesives, contact cement, tape residue, stickers, road tar, chewing gum, enamel spray paint.
Whether it gets the oil out of the gelcoat, probably not. But maybe once you've gotten all the solid rubber away, find a solvent for silicone oil. Research, research!
Sticky Butyl Tape-- Deadlights
Lots of opinions in this thread. How bout any "results?" I've got to re-bed my dead lights which were last bedded with sillycone. A local RV supply store has sticky butyl rubber tape (1"x3/16"x20ft) on sale. And it is white. So any experience from using this tape on deadlights? I want to avoid using anything out of a tube. The last time I did the job single handed, things slipped and slid around so much before the screws on the frames could be tightened that most of the tube contents were on my body. I think I still have those micro molecules of sillycone oil permanently infused into all 5-7 layers of my skin. Maybe also why I can't seem to hold on to a golf club anymore. But I've noticed that paint clean-up on my hands is very fast. If no experience with tape butyl since these posts, then I guess I'll be a sticky butyl rubber tape guinea pig. :D
powder coated window frames
Mike, glued to the boat like that I don't see how you communicate with your pc.? They bring you food, right?
I'm slabbing on the lexan (doesn't sound very elegant) so the beautyful frames (I give them a 90% grade) won't be used.
That's the plan.
BUT just in case, I feel I have to hold on to them for a little while longer because an albergeze aesthetic embarrassment storm might hit me.
Those aluminum frames were altered before powder coating to take thrubolts (machine screws), so they have holes in them!!!!
[DANG! just took a look using your blueline. Haven't seen those in a long time, they're covered and stored in the garage shop. It looks like NOT ENOUGH HOLES, top and bottom should have two more fastners each! Might work with what they have because the cabin side is mildly curved and the frames are flat - even after 40 years attached to the boat!!!!]
Practical Sailor's Waypoints - Stop That Leak!
Got an email from P.S. (5/04/11) because they still think I'm a subscriber.
I may have resubscribed because they DO cover a lot of product I wouldn't know about and a lot of fancy gear I can't afford.
But for Practical Sailor, when it comes to goop there is nothing new under the sun.
"The trick is to choose the right one..." they begin.
But when we get to the bottom of the page we aren't much wiser at all.
On Butyls, for instance, they say they "cure fast" and "stick well". If this were so they'd have to elaborate, but they don't. The tape butyl I use DOES NOT CURE. In fact it works because it doesn't. If you are talking about TUBE butyl and want it for plastic we'd have to know what solvents are in what tube butyl. Don't know that PS can go there. West Marine doesn't have any.
Tape butyl is sticky - but mostly to itself - it does make a good seal under pressure, but not too much pressure,
But the attribrute of butyl IS that it doesn't CURE like silicones, polysulfides, polyurethanes or polyethers. "Cures to a supple rubber." is the last sentence. But in no way does butyl compare with the other rubbers they mention.
.."can be used on polypropylene where polysulfide cannot." [see footnote]
Practical Sailor's favorite marine supplier for tube goop testing is West Marine - who do not carry tube or tape butyl (altho I haven't been there in a long while). Since we are too stoopid to make our own choices outside the marine catalog we should be getting information from our WISDOM SOURCE.
It is obvious that Practical Sailor can't find it either!
In this "Stop That Leak" piece they don't mention that polysulfides attack many plastics - and some plastics attack polyurethanes,. It would be important to warn loyal subscribers just what plastics you can't stop that leak with what tube rubbers. Polyurethanes aren't for stopping leaks anyway - they are for permanent bonds. Both products have industry and testing techies ignoring long term problems with UV in exposed joints.
This may be old stuff. I'm not a testing facility. These rubbers may have been improved for weather exposure. I'm not betting on it.
Practical Sailor keeps flogging Silicone ...."Sticks to almost everthing including glass, electrical insulation, and most metals."
"Don't use with polypropylene...." again that's a new one on me. Something I didn't know.
Can't find it on the net. If true, thanks PS for that knowledge.*
But we boat owners know why we DON'T STOP THAT LEAK WITH SILICONE.
Every boat forum knows this.
As a matter of fact Practical Sailor might have informed themslves as to what their public thinks... if they had done a little internet research instead of continuing their silicone myth. A sickness that comes from reading labels too much.
What the hell, what do I know?
Any movement of a joint with silicone caulking in it breaks the seal and allows water in. I know that.
If you smear silicone into a joint with silicone caulk in it to stop leaking - it won't happen.
Silicone doesn't stick to silicone, nor to the oil left behind in surfaces after you've troubled to carefully remove it.
Do any of the testers at PS do maintenance on their own boats?
They mention 'bedding compounds' avoiding the most famous: Dolfinite, opting for the more poetic Interlux 214. It bugs me because Dolfinite has a long standing rep and recognition as THE bedding compound that the "such as" Interlux product does not. The Dolfinite name is synonyimous with bedding compound - almost generic. Putting Interlux 214 forward is fishy and inappropriate - unless it has comparison tested better than all others - which I'm positive PS has never done.
That's OK, Practical Sailor has a problem with methodology.
They are aware of that. They carefully tell us how they set up their testing. On some products it's good enough.
On others, it's not conclusive, or complete, or correct.
I must be missing something!
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*It may be that Practical Sailor is trying to warn us off using silicone as a sealant for polypropylene because it is a "low surface energy" plastic.
Polyethylene is also a hard wax-like plastic. These plastics don't think epoxy is a glue.
And they may think likewise about some synthetic rubbers.
I would scuff non-conforming plastic surfaces and use tape butyl.
But you'll have to leave the fold and find it without Practical Sailort's guidance at a non-marine RV supplier.
If you insist on using silicone use NON-CORROSIVE silicone. It should say something like MANC or NC. Or neutral cure.
Is Butyl Truly That Good?
Silicone is truly evil.
But can it be said that a vinyl polymer, POLYISOBUTYLENE is truly good?
It is, afterall, a synthetic rubber compound - with a petroleum ancestry.
Our other choices besides silicone: polyurethane, polysulfide, perhaps polyether -
all OXIDIZE in time and will stiffen and crack.
PRO:
Butyl rubber "under the influence of heat, vibration, oxygen and ultra-violet radianion"
(In one test butyl survived without degrading 9000 hours in a UV booth.*) will not harden, crack, loose adhesion, crack or flow out of a joint.
Essentially remains permanently elastic. Butyl tape is chemically INERT.
It adheres to polycarbonate, acrylic, abs, stainless steel, wood, concrete and nearly anything else on a boat. Haven't tried it with polypropylene or p.ethylene.
It's self amalgamating: butyl tape combines with itself - self healing. It's solvent free. doesn't outgas.
Resists acids, alkali's and salts. Weather and age resistant. Doesn't oxidize. 20 year life, retains its tack.
Stores indefinitely.
As a tape it absorbs vibration and sound. Moisture and water vapor and air doesn't penetrate butyl rubber. Doesn't get mildewed.
Working with the tape is generally a much cleaner experience than tube apps. The material doesn't smear. Squeeze out can be removed easily and cleaned away with mineral spirit or xylene dampened cloth or paper towel.
CON:
Not an adhesive.
Doesn't come in clear.
Petroleum solvents will attack butyl.
Because it is an ever-sticky seam it does get dirity** (maybe there's a clever way to fix this?)
GOOD isn't perfect.:D
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*the standard longevity (weathering/UV) test in the industry is placing a product to be tested
in a box with UV mercury bulbs. "20 year life" is a tech spec, not a track record.
If you chew gum, it's probably food grade butyl. [I don't want to know!]
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**The Surebond SB-140 Skylight & Window Butyl Sealant I have mentioned,
not used yet, but
suggest experimenting with....has all the attributes of the tape version. But has 15 to 30% aliphatic solvent (mineral spirit, paint thinner, white gas, are considered aliphatic or 'weak' solvents.) in the mix - with 1% toluene. We assume, given the product description, that it's OK to use with chemically sensitive plastics like acrylic and polycarbonate.
ALWAYS stays sticky - but skins over. This minimizes dirt but an exposed seam can attract it. Need confirmation.
www.bestmaterials.com
[Just looked at the open tube of Bostik Chem-Calk 300 on the boat. Must have got it locally. have a globby screw stuck in the applicator. When a little is needed,, pull the screw and squeeze. It gets more difficult, and the caulk gets thicker, but it's still usefull after 6 months - or has it been a year??? Label says the contents is polyisobutylene/isobutylene/isoprene copolymer with calcium carbonate filler. Mineral spirits is the ONLY solvent listed.]
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Vendor quote: "SB-140....withstands extreme outdoor environments with very long life. Usefull for sealing difficult surfaces and joints. SUPERB ADHESION TO DIFFICULT MATERIALS INCLUDING SILICONE RUBBER AND STAINLESS STEEL....." Best Materials, 10.3oz Tube $4.25
Let's hope West Marine never smartens up.
