branko
Well-Known Member
I would like to mount thru hull transducer at the bottom of my boat. For sealing (gluing) I have info that SIKAFLEX glue-sealant is the best. Can you recommend type of SIKA product.
SIKAFLEX ?
- Thread starter branko
- Start date
SvenglishTommy
Well-Known Member
NOOOOOOO! You're info is incorrect. 3M is the best sealant, and no I'm not biased just because I work for them /forums/images/graemlins/tongue.gif
Either way, you want to use the less tenacious of them, so Sikaflex 291 or 3M 4200.
Either way, you want to use the less tenacious of them, so Sikaflex 291 or 3M 4200.
poter
Well-Known Member
Yeeeeeesssss I have used Sikaflex for years & its the best, just done my new thru hulls with 291, if you go Here You can download the product brochure.
good luck /forums/images/graemlins/smirk.gif
poter
good luck /forums/images/graemlins/smirk.gif
poter
AndCur
Well-Known Member
Word of warning if its a NASA transducer dont use Sikaflex as it causes the fittings to break due a reaction with the Sikaflex.
Lakesailor
Well-Known Member
How bonkers is that?
Let's produce a thru-hull fitting which will in all likelyhood be fitted with Sikaflex, and just to be awkward we'll make it from a material that reacts with Sikaflex.
Let's produce a thru-hull fitting which will in all likelyhood be fitted with Sikaflex, and just to be awkward we'll make it from a material that reacts with Sikaflex.
AndCur
Well-Known Member
Yes i know. If you do a search on the subject you will see that quite a few have cracked around the flange due to a reaction with the plastic. NASA say to use a silicone sealant.
nedmin
Well-Known Member
No its not bonkers! When I was in the music industry,there was a certain make of electronic organ that had "tabs" that went brittle and broke, this was found to be 2 different plastics on the same "tab" reacting with one another and going brittle.At the time I was very doubtful but once different ones were fitted no further probs.
Malcb
Well-Known Member
NASA say "It is advisable to avoid the use of mastic materials - use a form of proprietary silicone sealant"
Personally, I'd still use Sikaflex.
Personally, I'd still use Sikaflex.
Clyde_Wanderer
Well-Known Member
Now you have me worried.
Last week I removed and resealed the paddle wheel unit on my hull and sealed with sikaflex 292, with the addition of a ply wood backing on the inside.
I wasent happy with the look of the siliconey looking stuff that it was sealed with, which incidently, the plastic cockpit drain, hull fittings seem to be sealed with the same siliconey type stuff.
Can one get bronze hull C P drain fittings? as I would like to renew or change the old ones.
Last week I removed and resealed the paddle wheel unit on my hull and sealed with sikaflex 292, with the addition of a ply wood backing on the inside.
I wasent happy with the look of the siliconey looking stuff that it was sealed with, which incidently, the plastic cockpit drain, hull fittings seem to be sealed with the same siliconey type stuff.
Can one get bronze hull C P drain fittings? as I would like to renew or change the old ones.
pvb
Well-Known Member
Not necessarily...
NASA recommend using a simple silicone sealant because some marine sealants attack plastics, and most users don't know the differences between marine sealants. Polysulphide sealants such as 3M 101 and Life-Calk will attack most plastics. On the other hand, polyurethane sealant such as 3M 4200, Life-Seal and Sikaflex 291 will only attack acrylics such as ABS and Lexan.
Actually, I reckon the NASA advice is pretty good - if you ever need to replace a transducer it'll be much easier to do if silicone was used as a sealant.
NASA recommend using a simple silicone sealant because some marine sealants attack plastics, and most users don't know the differences between marine sealants. Polysulphide sealants such as 3M 101 and Life-Calk will attack most plastics. On the other hand, polyurethane sealant such as 3M 4200, Life-Seal and Sikaflex 291 will only attack acrylics such as ABS and Lexan.
Actually, I reckon the NASA advice is pretty good - if you ever need to replace a transducer it'll be much easier to do if silicone was used as a sealant.
Dougal
Well-Known Member
Re: Not necessarily...
I fitted new Spinlock rope clutches last year. They all had stickers on saying DO NOT USE POLYURATHANE SEALANTS.
Same reason i guess
I fitted new Spinlock rope clutches last year. They all had stickers on saying DO NOT USE POLYURATHANE SEALANTS.
Same reason i guess
Strathglass
Well-Known Member
[ QUOTE ]
Yes i know. If you do a search on the subject you will see that quite a few have cracked around the flange due to a reaction with the plastic. NASA say to use a silicone sealant.
[/ QUOTE ]
Yes,
Ask ROWANA about that.
I don't know what sealant had been used when it was originally fitted but we had to make a hasty retreat into Burghead harbour as a result of a NASA paddle wheel housing cracking apart.
Iain
Yes i know. If you do a search on the subject you will see that quite a few have cracked around the flange due to a reaction with the plastic. NASA say to use a silicone sealant.
[/ QUOTE ]
Yes,
Ask ROWANA about that.
I don't know what sealant had been used when it was originally fitted but we had to make a hasty retreat into Burghead harbour as a result of a NASA paddle wheel housing cracking apart.
Iain
pvb
Well-Known Member
Spinlock...
On a few Spinlock clutches, polyurethane sealant is discouraged because it can affect the side plates, causing a chalking effect. The installation instructions for some Spinlock products include the warning "Never use polysulphide-based sealants which can degrade the product. (Also some polyurethane sealants, ie Sika291, may cause damage.)".
On a few Spinlock clutches, polyurethane sealant is discouraged because it can affect the side plates, causing a chalking effect. The installation instructions for some Spinlock products include the warning "Never use polysulphide-based sealants which can degrade the product. (Also some polyurethane sealants, ie Sika291, may cause damage.)".