smo Posted March 27, 2008 Share Posted March 27, 2008 Is it possible to seal seams between aluminium plates/panels using fibreglass tape?? What needs to be done to achieve a good bond? Is it better to use polyester or epoxy resin? Quote Link to comment Share on other sites More sharing options...
Paul Humphreys Posted March 27, 2008 Share Posted March 27, 2008 You can get the proper stuff for sicking wings on to cars. Silkaflex I think its called. Paul Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted March 27, 2008 Share Posted March 27, 2008 Sikaflex is marvellous stuff. It's used a lot for glueing bits to boats, and bits of boat to each other! It comes in a variety of flavours, I'm guessing there's a vehicle/panel specific version. Quote Link to comment Share on other sites More sharing options...
smo Posted March 27, 2008 Author Share Posted March 27, 2008 Sikaflex is a "silicon type" sealant (from the marine industry originally, moisture curing, bloody strong and excellent stuff for just abouit everything!), but not entirely what im after, as ive already got 6 tubes of it at the ready....i was hoping to use a biaxial glass tape with resin to make "invisible" seals along the inside of some ali panels on the D-Lander.... Quote Link to comment Share on other sites More sharing options...
Happyoldgit Posted March 27, 2008 Share Posted March 27, 2008 Sikaflex is good, expensive but good ..as is Tiger Seal. You can get brushable or gun applicator seam sealers from all decent auto paint factors. Quote Link to comment Share on other sites More sharing options...
jameslwt Posted March 27, 2008 Share Posted March 27, 2008 Epoxy will give a far superior bond, but is harder to mix and approx twice as expensive. It can only be used with woven glass - so you should be ok with tape, but I wouldn't use this method for an invisible join. Sikaflex is more than just marine sealant - on modern vehicles where the windows are bonded in - (such as transit van side windows - vehicles with the black band around the outside of the glass) they all use sikaflex vehicle adhesive. I can't remember it's exact type No, but you can get it from bodyshops/car window repair places etc. When I originally bonded some side windows into my 110 before doing it properly with the sliding windows, I used this stuff, but I was warned before about how sticky it was. It was a nightmare to apply as it is so thick and tacky, but when I came to remove the windows it took for ever as the glass was bonded in so well (obviously didnt really want to smash windows apart!!) Cheers James Quote Link to comment Share on other sites More sharing options...
smo Posted March 27, 2008 Author Share Posted March 27, 2008 But will epoxy work to the ali - ive done a fiar bit of marine work in the past, using both fibreglass and sikaflex so am familiar with both...just not when it comes to mixing wiht ali Quote Link to comment Share on other sites More sharing options...
jameslwt Posted March 27, 2008 Share Posted March 27, 2008 Yes it will - just make sure, like painting, that it is very clean and there is a good key to the surface. Have a look at the West Epoxy website - I would recommend West Systems above the rest. There are other brands around like Blue Gee, SP And Epiglass, but having worked in the marine industry for most of my working life, I would not use anything but West given the choice. They have a variety of fillers/additives to thicken up the resin so you can turn it into a filler/glue/gap filler/whatever you want, just by adding differnt additives. Then go online and buy it from CFS grp supplies mail order as it tends to be much cheaper. cfs.net I think. HTH Quote Link to comment Share on other sites More sharing options...
jameslwt Posted March 27, 2008 Share Posted March 27, 2008 And as I have been told many times......lots of aircraft are held together with epoxy based adhesives, and they have ali skins. If it's good enough for them....! Quote Link to comment Share on other sites More sharing options...
smo Posted March 27, 2008 Author Share Posted March 27, 2008 Excellent, thanks James Quote Link to comment Share on other sites More sharing options...
western Posted March 27, 2008 Share Posted March 27, 2008 And as I have been told many times......lots of aircraft are held together with epoxy based adhesives, and they have ali skins. If it's good enough for them....! Hmmm, pinch of salt time, for that comment, most Alloy covered aircraft are rivetted construction, some parts are bonded but not the primary [main] structure, newer aircraft made of carbon fibre composites are fully bonded primary structure though. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted March 28, 2008 Share Posted March 28, 2008 For those of you that have a good memory. Ford J car. Maclaren as it was in the 1960's. They both were building aluminium honeycomb chassied cars. They both had the same problem with the bobding agent not bonding. The story at the time was You couldn't get the aluminium clean and keep it clean long enough to use the bonding agent. Reason. Aluminium oxidises immediately that it is cleaned. Anybody crare to verify that ? mike Quote Link to comment Share on other sites More sharing options...
smo Posted March 28, 2008 Author Share Posted March 28, 2008 The oxidisation bit is true, however it should be possible to clean it enough to manage before any decent amount of oxidisation occurs. Quote Link to comment Share on other sites More sharing options...
tacr2man Posted March 28, 2008 Share Posted March 28, 2008 The sikaflex that is the type that is used for bonding in windscreens with air bag vehicles will be strong enough to bond any panels as the windscreen will break before the bond . It would also solve any inter metal corrosion problems . JMHO Quote Link to comment Share on other sites More sharing options...
smo Posted March 28, 2008 Author Share Posted March 28, 2008 Ok ok - enough about Sikaflex, it isn't suitable to this application, hence why im considering the use of fibreglass - i know how great it is, im a "user" already, but its not for this job!!! So, back to fibreglass and ali..... Quote Link to comment Share on other sites More sharing options...
rtbarton Posted March 28, 2008 Share Posted March 28, 2008 Ok ok - enough about Sikaflex, it isn't suitable to this application, hence why im considering the use of fibreglass - i know how great it is, im a "user" already, but its not for this job!!!So, back to fibreglass and ali..... If you mean woven tape I'd be inclined to avoid it. I'd be worried that moisture could get in and stay there, causing corrosion. Quote Link to comment Share on other sites More sharing options...
Happyoldgit Posted March 28, 2008 Share Posted March 28, 2008 Ok ok - enough about Sikaflex, it isn't suitable to this application, hence why im considering the use of fibreglass - i know how great it is, im a "user" already, but its not for this job!!!So, back to fibreglass and ali..... Perhaps if you explained the specific application you have in mind in a bit more detail then you may get the kind of answers you are obviously seeking. Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted March 28, 2008 Share Posted March 28, 2008 The oxidisation bit is true, however it should be possible to clean it enough to manage before any decent amount of oxidisation occurs. I agree entirely about the immediate oxidisation, but I'd rather hope the cure lies in technology developing since the 1960's, and thus able to bond as effectively to lightly oxidised aluminium as to the 'impossible' pure aluminium of a vapour build. Put lightly oxidised in context, I mean something cleaned in the last 5 minutes, not something cleaned 5 weeks ago... When making electrical joints between aluminium componants, such as power bus bars, the problem of immediate oxidisation was severe. This would cause acoustically noisy potential drop across the joint face. The cure was in attention to detail, the final clean would be to coat the surface with Petroleum Jelly, then wipe the surface with a file card, kept bagged in plastic, purely for this purpose. In this way the PJ would be dragged into the scratch made by the file card bristle, preventing the air (oxygen & water) access to the metal. That gives an indication as to how quickly oxidisation will form on clean aluminium. HTH Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted March 28, 2008 Share Posted March 28, 2008 If you mean woven tape I'd be inclined to avoid it. I'd be worried that moisture could get in and stay there, causing corrosion. The problem to be overcome is that aluminium flexes but resin doesn't. This is in the detail, a big fibreglass panel will flex over a large area, but push the movement too far and the resin cracks, allowing moisture and oxygen into the glass strands, and the base metal. I would never match tape to thin metal, as the tape is too rigid to follow the metal, leaving voids which fill with resin, which is structurally weak. Remember that glass or carbon fibre is strong because the glass / carbon is strong. The resin is there to hold the strands in a fixed relationship to each other, so the load can be shared between the strands. The fibre / resin relationship is symbiotic, each helps the other. I have successfully bonded glass fibre to thin vibrating rusty steel, in a method that lasted. I used glass tissue, the very lightest and thinnest of mat, together with a light application of resin, because this would follow all the surface variations in the metal. There was no loose rust, the surface was cleaned with an electric wire brush, but I didn't have a blast cabinet at the time, so the steel certatinly wasn't rust free. The tissue layer clearly smoothed out all the minor imperfections, and gave a suitable base layer for the chopped strand mat to bond to. Obviously I added mechanical strength by layering CSM on top of the tissue. I totally covered the pressed steel frame of a rotary lawn mower, so had a Techumsah engine bolted to it. Despite the vibration, the glass fibre to steel joint never broke down, over several years of use, so I feel confident the bond was mechanically good, and prevented water & oxygen ingress. Cheers. Quote Link to comment Share on other sites More sharing options...
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