Plastic welding

[Themselves]

broke the dometic door shelf thing. Can’t believe how much they want for a new one. It’s only a plastic container not the entire thing. However, I recently bought a plastic welding tool to fix a crack in the bumber. It came with staples to melt into the plastic. The very thing.

 

[Vanman]

Oooo nice - do you have a link for that?

 

[Themselves]

Oooo nice - do you have a link for that?

its a Sealey 30w rechargeable SDL14.

 

[The Coops]

Ali Express £18 for kit!

 

[ChrisL]

Ali Express £18 for kit!

Just looking on ebay they're over £100 that's a big mark up.

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[Nirvanauk]

Just something else I didn't know I needed until now...

 

[Vanman]

Ali Express £18 for kit!

Hmmm can't find that one ... do you have a link?

 

[Reallyretired]

I have one. Repairs can be stronger than the original. Mine was cheap possibly Temu, can't remember.

 

[Gromett]

broke the dometic door shelf thing. Can’t believe how much they want for a new one. It’s only a plastic container not the entire thing. However, I recently bought a plastic welding tool to fix a crack in the bumber. It came with staples to melt into the plastic. The very thing. View attachment 975703View attachment 975704View attachment 975703

Not meaning to be picky and as a point of interest for future.. The staples are supposed to be 90° to what you have done. So they run along the crack, back and forward across it.

Like this;

 

[Gromett]

PS: Looks like you have only welded on one side. May be worth doing a few on the other side in the correct orientation?

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[The Coops]

Hmmm can't find that one ... do you have a link?

Put in plastic welding kit in the search bar on Ali express there are pages of them from about £7

 

[Vanman]

Put in plastic welding kit in the search bar on Ali express there are pages of them from about £7

Ah - sorry, thanks. I thought you meant a Sealey one.

 

[GMLS]

broke the dometic door shelf thing. Can’t believe how much they want for a new one. It’s only a plastic container not the entire thing. However, I recently bought a plastic welding tool to fix a crack in the bumber. It came with staples to melt into the plastic. The very thing. View attachment 975703View attachment 975704View attachment 975703

Very satisfying

 

[KNWH]

Not meaning to be picky and as a point of interest for future.. The staples are supposed to be 90° to what you have done. So they run along the crack, back and forward across it.

Like this;

View attachment 975919

I think the optimum orientation depends on the application and the shape of the staples used.
On the example you have shown: crack over a large area on what looks like a fairly thin and flexible panel, with snakelike staples, I agree the staples should be like that.
On the OP’s example his staples are more zig-zag and if used along the join there would be very little depth of material holding in each zig or zag. In his method each staple looks very well secured, but the join depends on the strength of the tensile strength of the staple.
A couple more from the opposite side would certainly be belt and braces.

 

[Gromett]

I think the optimum orientation depends on the application and the shape of the staples used.

I disagree. The shape of the staples should be chosen based on the material being used. The shorter wiggle ones are for thinner plastic or non structural. But should still be used along the crack.
The ones with big wiggles are for thicker plastic or for structural plastics.

In this case he has used staples that are not the most optimal for the job. Using this type would have been better for this job.

I tried to avoid being a know it all or lecturing. But I see many people using these the wrong way and it will end up with a much weaker joint and I don't know how to phrase it better

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[KNWH]

I disagree. The shape of the staples should be chosen based on the material being used. The shorter wiggle ones are for thinner plastic or non structural. But should still be used along the crack.
The ones with big wiggles are for thicker plastic or for structural plastics.

In this case he has used staples that are not the most optimal for the job. Using this type would have been better for this job.

View attachment 976101

I tried to avoid being a know it all or lecturing. But I see many people using these the wrong way and it will end up with a much weaker joint and I don't know how to phrase it better

Well I certainly don’t want to have an online argument as they rarely end well!
I totally agree that the staples you suggest must be used as you say.
As a mechanical engineer I still think that the staples the OP used, although they may not be the optimal solution, are best used as he did to avoid edge breakout, but that’s just my personal view.
If I ever get one of these things (and it’s the sort of gadget you look for things to use it for, so you can justify getting one ) then I’d probably do a few trials to see how things performed.

 

[Gromett]

Well I certainly don’t want to have an online argument as they rarely end well!
I totally agree that the staples you suggest must be used as you say.
As a mechanical engineer I still think that the staples the OP used, although they may not be the optimal solution, are best used as he did to avoid edge breakout, but that’s just my personal view.
If I ever get one of these things (and it’s the sort of gadget you look for things to use it for, so you can justify getting one ) then I’d probably do a few trials to see how things performed.

At the end of a crack you should in some cases put them across like he did especially if the crack runs to the edge of the material as it does here. But through the length of the crack you want as many crossings as possible to spread any loads.

 

[Diabalo]

One of the best ways on thick plastic is to put the staple across the crack and as it goes in twist it slightly, that way it buries it'self.

 

[Gromett]

One of the best ways on thick plastic is to put the staple across the crack and as it goes in twist it slightly, that way it buries it'self.

You should twist which ever way you put them in. Just a little bit.

 

[Themselves]

PS: Looks like you have only welded on one side. May be worth doing a few on the other side in the correct orientat

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[Themselves]

I used superglue to fix the two broken bits together and the staples are to ensure they stay stuck.

 

[KNWH]

At the end of a crack you should in some cases put them across like he did especially if the crack runs to the edge of the material as it does here. But through the length of the crack you want as many crossings as possible to spread any loads.

Many crossings certainly spreads the load. My concern is, with the type of staple the OP used, the staple, if used along the join, is never far enough from the edge to avoid the stresses causing ‘plastic deformation’. That is used in the engineering sense to mean the material does not recover its shape when the load is removed (sorry if you already know this and it comes across as patronising) and the join failing due to that mechanism.
Anyway, feel free to reply, but I’ll leave it at that now.

 

[RM_Marine]

Super glues and baking soda mixed the dyson the other day well two years ago after I dropped it

 

[KNWH]

At the end of a crack you should in some cases put them across like he did especially if the crack runs to the edge of the material as it does here. But through the length of the crack you want as many crossings as possible to spread any loads.

Many crossings certainly spreads the load. My concern is, with the type of staple used, the staple is never far enough from the edge to avoid the stresses causing ‘plastic deformation’. That is used in the engineering sense to mean the material does not recover its shape when the load is moved (sorry if you already know thi

 

[KNWH]

Not sure why this half finished message appeared too, sorry!

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[Gromett]

Many crossings certainly spreads the load. My concern is, with the type of staple the OP used, the staple, if used along the join, is never far enough from the edge to avoid the stresses causing ‘plastic deformation’. That is used in the engineering sense to mean the material does not recover its shape when the load is removed (sorry if you already know this and it comes across as patronising) and the join failing due to that mechanism.
Anyway, feel free to reply, but I’ll leave it at that now.

It was the wrong staple for this application as I said previously. But even so I think installing it in the correct orientation more of them would have been better long term.
Having a single point of join in a specific distance will always be more likely to move from the elastic deformation to plastic deformation state than if there were multiple points of contact spreading the load (reduced leverage).

Anyway, The OP said he also superglued it so that in combination with the staples should ensure it will hold irrespective.

 

[Gromett]

I used superglue to fix the two broken bits together and the staples are to ensure they stay stuck.

I am sure it will be fine. Just gnashing our gums

 

[dunnah01]

The OP has to installed the staples to develop the best anchorage bond strength in the plastic so will work well.

 

[scotzsue]

Ooooh staplegate
Think I want one.

 

[pagey]

I use a wood screw put in my soldering iron and melt a bit of the same type of plastic and melt them together, saw it on you tube

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