Adhesive for PP

[Basil]

Hi, I am trying to make a cowl from a funnel to affixed to a cylindrical   frame to make a cowl. I am looking for an adhesive to fix the poly-propylene 'Cowl' to the wooden ( balsa/ply) frame.  whats the best least messy/easy sand type please .

I am also looking for a suitable paint for the wood(Easy) and the PP ?.

many thanks.

Bas

 

Edited December 1, 2023 by Basil

[leccyflyer]

Polypropylene is tricky stuff to get an adhesive bond to. A couple of potential (expensive) candidates are Fusion and Stabilit Express. They could do the job, provided you scuffed up the gluing area to give them something to grab onto.

[Paul De Tourtoulon]

Other than a mechanical way as in screws, I have never found any glue that will stick to polypropylene .

[Martin Fraser]

I've not used this Shoe Goo on PP before but it's great on other plastics such as clear PETG for cockpit glazing etc. It remains flexible and the makers say you can use it to repair wet suits and even shoes!

 

Might be worth a try.

[Basil]

1 hour ago, leccyflyer said:

Polypropylene is tricky stuff to get an adhesive bond to. A couple of potential (expensive) candidates are Fusion and Stabilit Express. They could do the job, provided you scuffed up the gluing area to give them something to grab onto.

 have in anticipation given the PP a good scuff.

[Basil]

36 minutes ago, Paul De Tourtoulon said:

Other than a mechanical way as in screws, I have never found any glue that will stick to polypropylene .

That has been my experiance so far, but.......

[Geoff S]

Polypropylene

6 hours ago, Martin Fraser said:

I've not used this Shoe Goo on PP before but it's great on other plastics such as clear PETG for cockpit glazing etc. It remains flexible and the makers say you can use it to repair wet suits and even shoes!

 

Might be worth a try.

 

Wetsuits are quite easy to repair.  When we first started sailing in the 1970s we made our own from kits and the rubber glued easily edge to edge, so it's not necessarily a good guide to the adhesive's efficacy on polypropylene. 

 

I built a model yacht some years ago which had a moulded plastic hull and the only thing that worked as an adhesive was Stabilit Express, which is certainly good but expensive .

[John Lee]

15 hours ago, Geoff S said:

I built a model yacht some years ago which had a moulded plastic hull and the only thing that worked as an adhesive was Stabilit Express, which is certainly good but expensive .

 

Agreed, but it does seem to have a very long shelf life. I bought this pack 10+ years ago & keep it for those occasional difficult jobs where nothing else will do. It still seems to work as good as new.

 

[Basil]

On 01/12/2023 at 10:22, leccyflyer said:

Polypropylene is tricky stuff to get an adhesive bond to. A couple of potential (expensive) candidates are Fusion and Stabilit Express. They could do the job, provided you scuffed up the gluing area to give them something to grab onto.

Hi Leccy, had a look at those two products that you named;

Stablitt is ' Not for PP' its actually on the label.

Fusion, from, 'Delux Material', they claim that it sticks any thing that can be glued, but is carefully labelled. I have contacted them , but they have not got back.( I assume its doubtful)

I have found some , well 1 or 2, expensive but made for PP.Lots available for large users, need guns etc. I will let you know. (50ml £20 odd).

I have been playing with an Aldi 'Hot melt gun' that I have. Ran some tests,If you

 let the gun get really hot it proved to have some adhesion to PP , but it has to be HOT.Adhesion ranges from stuck very well, would not separate  easily, to peelable with some effort.

 The bond I want between balsa/ply will not be under a great deal of load ( PP cowl to a balsa) so I will most likely try the hot melt road, let the gun stew for a bit.

 I have tested the hot melt balsa to balsa pulls apart but tears off the top layer of wood, does not seperate, so ok.

Bas

Edited December 2, 2023 by Basil

[Paul De Tourtoulon]

I have some super PP glue to repair pools etc and it cost an arm and a leg, it says that it will stick anything, but looking at the way it comes off of its own PP cartridge, it won't stick PP.

[Engine Doctor]

Best way to glue PP is to find another material. Its too waxy to glue. Have you tried gluing a candle stick? It can be welded but not glued. Why are you useing it ? Virtually any shape cowl can be built using balsa block method. You should be able to find a post with pics on here with a search . 

 Tack Glue blocks of balsa to the front of fuz filling inside with blicks were you want to sand to shape and might sand through , especially on corners. This can be done very quickly with cyano . Then plane and sand to shape. When happy with exterior cut from fuz and carve out inside . A dremel is very handy for this it can all be toughened up by appling some cyano or finishing epoxy before final sanding and finishing.

 

Edited December 2, 2023 by Engine Doctor

[Engine Doctor]

Pics for making a Balsa cowling . A Davids plane then a sanding block to shape . This took a couple of hours . 

[Basil]

2 hours ago, Engine Doctor said:

Best way to glue PP is to find another material. Its too waxy to glue. Have you tried gluing a candle stick? It can be welded but not glued. Why are you useing it ? Virtually any shape cowl can be built using balsa block method. You should be able to find a post with pics on here with a search . 

 Tack Glue blocks of balsa to the front of fuz filling inside with blicks were you want to sand to shape and might sand through , especially on corners. This can be done very quickly with cyano . Then plane and sand to shape. When happy with exterior cut from fuz and carve out inside . A dremel is very handy for this it can all be toughened up by appling some cyano or finishing epoxy before final sanding and finishing.

 

Hi, I am making a Scottish Pioneer, at the rear of the cowl is an outward facing , thin , upturn. Have you ever tried to make one. I used PP because I used a funnel, or rather part of it , just a thin band ,say 1/2 ". It has just occurred to me that I suppose I could have tried to use the funnel as a mould and used very thin ply inside and then cut a band from it. thats my excuse, at least for now. I will see how the hot melt goes.

Bas

[John Lee]

3 hours ago, Basil said:

Stablitt is ' Not for PP' its actually on the label.

 

So it is!

 

Good job I never noticed as I don't read German because I have used it successfully a few times over the years. 😀

 

[Engine Doctor]

18 hours ago, Basil said:

Hi, I am making a Scottish Pioneer, at the rear of the cowl is an outward facing , thin , upturn. Have you ever tried to make one. I used PP because I used a funnel, or rather part of it , just a thin band ,say 1/2 ". It has just occurred to me that I suppose I could have tried to use the funnel as a mould and used very thin ply inside and then cut a band from it. thats my excuse, at least for now. I will see how the hot melt goes.

Bas

Good luck with build, hopes it goes well . Pics ?

[Christopher Wolfe]

Here in Australia I have successfully used this product to glue core-flute plastic to aluminium when framing up a model transportation box. Selleys plastic adhesive

 

It did a remarkable job (considering that I was a bit skeptical). Apparently the primer modifies the polar properties of the surfaces to be joined.

 

I suppose that similar products are available in the UK.

 

* Chris *

[Basil]

1 hour ago, Christopher Wolfe said:

Here in Australia I have successfully used this product to glue core-flute plastic to aluminium when framing up a model transportation box. Selleys plastic adhesive

 

It did a remarkable job (considering that I was a bit skeptical). Apparently the primer modifies the polar properties of the surfaces to be joined.

 

I suppose that similar products are available in the UK.

 

* Chris *

Hi Chris, I would hazard a guest and say that there are a small number of  products that may fall into this group here in UK. Those that are non industrial  are very expensive and thin on the ground. It seems that particular adhesive is sold in Aussy and NZ.

Thanks Bas

Edited December 3, 2023 by Basil

[Phil Green]

Anything they make glue bottles out of is generally not good to glue to 😁

[Basil]

2 hours ago, Phil Green said:

Anything they make glue bottles out of is generally not good to glue to 😁

Thanks for your comment Phil.

Bas