Glueing to fibreglass

[vfxdog]

Seems to be some good knowledge here- I'm looking for suggestions as to the best kind of adhesive to use to stick some thin steel brackets (16 gauge; approx .060") to the inside of a fairing. The fairing is approx 20 years old and is painted (mainly overspray) on the inside. Do I need to rub down the surface? Would I need to use a small overlay mat? The brackets are primered over galvanising, and have pads for where they would attach to the fairing..

[fLaThEaD FreD]

Ph. me on 0800-80-3001 business hours and i'll sort it for you.I have something that F1 put their bodies together with........cheers, Peter

Seems to be some good knowledge here- I'm looking for suggestions as to the best kind of adhesive to use to stick some thin steel brackets (16 gauge; approx .060") to the inside of a fairing. The fairing is approx 20 years old and is painted (mainly overspray) on the inside. Do I need to rub down the surface? Would I need to use a small overlay mat? The brackets are primered over galvanising, and have pads for where they would attach to the fairing..

[CookMySock]

Its way cool that professionals speak up here and help out the newbies.

But for those still wondering ; Gluing a new bit of fibreglass to a fully-cured piece is called a secondary bond. The existing cured surface has to be "keyed" or roughened up, as you would expect, so roughen it up fully with some 60grit. Do this immediately before you continue with the next step. If its structural, then take care not to damage the existing layup fibres.

I wouldn't scuff the brackets up coz it will disturb the primer. You could clean them with meths though.

Cut a small glass mat with some overlap to go between the parts, and another mat or three to over the top of the bracket. Use cloth, not chopped-strand mat.

The hardest part is going to be getting the brackets' alignment correct, so if you can put a dot of automotive filler, or superglue on all the joins (put pads under first) and leave it to fully cure. Then pull the fairing off and see if everything is still attached. If so, then the rest is easy.

Temporarily dry-fit all the cloth patches in place to check if the fit etc is cool. Remove the patches. Then mix your resin and thoroughly wet the areas with a small brush - "push" the resin in with the tip of the brush. If you knock one of the brackets off, then wipe all the resin off this area and just finish the other brackets off - don't waste time here - come back to this one later, or your resin will go off and you will be up shit creek.

Place the patches over the wet resin and tamp them down with the tips of a DRY brush, a narrow plastic spatula, or a small roller. Get all the air out. You dont need to add so much resin that it runs everywhere - just enough to get the air out.

Get some nylon fabric like this stuff http://www.aristaflagstore.com/products.asp?cat=18 (ask your mrs, or get introduced to her cute sewing friend - a good excuse) and cut little patches that fit completely over the repair, and tamp them down with your dry brush until the resin comes through the nylon. Smooth it down real well and get all the wrinkles out.

Now keep it warm (20oC min) and PISS OFF AND DONT TOUCH IT ! Put a blanky over it and use a space heater with thermostat if its out in the cold shed. If you are using polyester resin, then come back the next day. If you are using epoxy, then leave it for two - three days.

Now once its fully cured (harrrrrd!!!!), carefully peel the surface' nylon fabric off and prepare to be amazed.

Really, you should clamp a wet piece of patch between the joints, but that is rather difficult in this case. The hardest part with glassing is getting all ten brackets to sit in exactly the right place and stay there, while you use your eleventh arm to put some glue on and roll it down, and then wait for 20mins for it to go off.

Yep, this is just one method. I learned a lot from listening to the fibreglass airplane boys. Others will add corrections and tips I hope.

DB

[fLaThEaD FreD]

my magical stuff can avoid all that. This product chemicly welds steel to fibreglas and most plastics. Has gap filling qualitys.2-3minute working time and 7minutes to fully usable. 50ml twin tube.$18 plusGST.

Its way cool that professionals speak up here and help out the newbies.

But for those still wondering ; Gluing a new bit of fibreglass to a fully-cured piece is called a secondary bond. The existing cured surface has to be "keyed" or roughened up, as you would expect, so roughen it up fully with some 60grit. Do this immediately before you continue with the next step. If its structural, then take care not to damage the existing layup fibres.

I wouldn't scuff the brackets up coz it will disturb the primer. You could clean them with meths though.

Cut a small glass mat with some overlap to go between the parts, and another mat or three to over the top of the bracket. Use cloth, not chopped-strand mat.

The hardest part is going to be getting the brackets' alignment correct, so if you can put a dot of automotive filler, or superglue on all the joins (put pads under first) and leave it to fully cure. Then pull the fairing off and see if everything is still attached. If so, then the rest is easy.

Temporarily dry-fit all the cloth patches in place to check if the fit etc is cool. Remove the patches. Then mix your resin and thoroughly wet the areas with a small brush - "push" the resin in with the tip of the brush. If you knock one of the brackets off, then wipe all the resin off this area and just finish the other brackets off - don't waste time here - come back to this one later, or your resin will go off and you will be up shit creek.

Place the patches over the wet resin and tamp them down with the tips of a DRY brush, a narrow plastic spatula, or a small roller. Get all the air out. You dont need to add so much resin that it runs everywhere - just enough to get the air out.

Get some nylon fabric like this stuff http://www.aristaflagstore.com/products.asp?cat=18 (ask your mrs, or get introduced to her cute sewing friend - a good excuse) and cut little patches that fit completely over the repair, and tamp them down with your dry brush until the resin comes through the nylon. Smooth it down real well and get all the wrinkles out.

Now keep it warm (20oC min) and PISS OFF AND DONT TOUCH IT ! Put a blanky over it and use a space heater with thermostat if its out in the cold shed. If you are using polyester resin, then come back the next day. If you are using epoxy, then leave it for two - three days.

Now once its fully cured (harrrrrd!!!!), carefully peel the surface' nylon fabric off and prepare to be amazed.

Really, you should clamp a wet piece of patch between the joints, but that is rather difficult in this case. The hardest part with glassing is getting all ten brackets to sit in exactly the right place and stay there, while you use your eleventh arm to put some glue on and roll it down, and then wait for 20mins for it to go off.

Yep, this is just one method. I learned a lot from listening to the fibreglass airplane boys. Others will add corrections and tips I hope.

DB