Shinker & Stretcher - Issues

[novice_mechanic]

I am currently in the process of applying some repair patches to the bug & thought of buying a hand-operated shrinker and stretcher to create complex patches more easily. So I did for 150 Euros on Amazon. Before buying one, I did some research and found out that these machines don't work straight out of the box. Collectively, I would say I saw a total of 3 Hours' worth of clips on YouTube on how to get Shinkers & Stretchers in good working order.

Upon receiving mine, I put it on a vice and got straight to using it, but as expected, it did not function properly. The Stretcher worked to some degree, but on the other hand, the Shrinker, the one I needed to use, did not, so I got to work on that.

Based on YouTube recommendations, I began by disassembling the machine, and I immediately noticed the First Issue. The other faces, besides the Jaws, on which the whole mechanism slide on, were all uneven & at times the Shrinker would bind. Sanded the side faces with 220 Grit, working up to 320 grit on all pieces until they were smooth (See Image 1). This made the inner workings of the Shrinker work way smoother, but I have encountered another issue.

Image 1:

The Second Issue occurs when the jaws engage with the sheet metal and initiate the shrinking process to pinch the material together, the jaws tend to slide, indicating that they may not be gripping the sheet metal properly. I then proceeded to dismantle the Shrinker Jaws again to clean out any debris that may clog them, which could prevent them from gripping properly. This too did not work, so I cleaned the Jaws a second time and this time filed the teeth of the Jaws (See Image 2). This gave them somewhat a better grip, but despite these amendments, they did not contribute to any improvements.

Image 2:

On top of these attempts to make the Shrinker work properly, I:

1. Bent the retaining clip tips to 90 Degrees & made sure they are the same height (See Image Below)

2. Made sure that the thickness of the sheet metal did not exceed the maximum amount of the Machine (See Images Below)

At this point, I am considering replacing the Shrinker jaws with a better-quality pair. However, before I go down that path, I’d appreciate any recommendations or guidance on what I might be overlooking or doing incorrectly that’s causing them not to function correctly.

Have any of you experienced similar issues with the jaws sliding during operation and failing to grip the sheet metal effectively? I’m very interested in hearing if there are any further adjustments I can try.

Thank you so much for your attention and participation in this issue

 

[tom2207]

welcome to the forum ,,, try a light aluminium part first ,, to see if the action is right , but starting into 1.2 with a cheap shrinker is at best ,,,, ambitious .

 

[novice_mechanic]

I understand. Tried using it with a piece of thick paper I had on hand as soon as I finished filing the teeth of the Jaws, and it worked as a charm to be honest. I don't like to sacrifice for thinner metal for patchwork, as this sheet metal is the right thickness for the car I am working on. Thanks for your prompt reply btw

 

[tom2207]

I understand. Tried using it with a piece of thick paper I had on hand as soon as I finished filing the teeth of the Jaws, and it worked as a charm to be honest. I don't like to sacrifice for thinner metal for patchwork, as this sheet metal is the right thickness for the car I am working on. Thanks for your prompt reply btw

it was only to check the machine worked ,,, after that you know its working in theory , its just about getting pressure ,,, have you seen even a small Eckold

 

[8ob]

I bought the Frost version of Shrinker and stretcher, aside of the jaws clogging I noticed you only get a few goes at the shrinking/stretching before you have to anneal the steel and go again. I put it down to work hardening.

Bob

 

[tom2207]

I bought the Frost version of Shrinker and stretcher, aside of the jaws clogging I noticed you only get a few goes at the shrinking/stretching before you have to anneal the steel and go again. I put it down to work hardening.

Bob

what gauge of steel were you working with ?

 

[novice_mechanic]

it was only to check the machine worked ,,, after that you know its working in theory , its just about getting pressure ,,, have you seen even a small Eckold

Yes I did but they are wayyy out of my price range. I can see its superior than the one I have but the price it not justified for the ammount of usage i am going to get out of it. Once i am finished with the patchwork its going to sit in the corner for a long time before i get to use it agian.

I did some window shopping around where I live but there the same ones that I have but overpriced in my opinion.

This is the one I have:

 

[tom2207]

Yes I did but they are wayyy out of my price range. I can see its superior than the one I have but the price it not justified for the ammount of usage i am going to get out of it. Once i am finished with the patchwork its going to sit in the corner for a long time before i get to use it agian.

I did some window shopping around where I live but there the same ones that I have but overpriced in my opinion.

This is the one I have:

it may be as simple as using a longer handle ,,, a genuine lancaster can just about do 1.2 on a good day ,,, just .

 

[Stuartg1]

I have one of the metz/ generic sets, they work perfectly on .8 and just about on 1mm, No way would I expect them to work on anything thicker, they are however rated at 1.2mm but only for ally

 

[novice_mechanic]

it may be as simple as using a longer handle ,,, a genuine lancaster can just about do 1.2 on a good day ,,, just .

Bought it just because of the 1.2mm maximum thickness I am able to use on the machince as advertised and thought I was in range. Maybe I have to count my losses on this one and move on.

Could be possible to get better results using a tucking fork? I know its a lengthy process but as explained I was considering purchasing a higher quality replacement jaws foy my Shrinker. Do you think the will issue still remain if i did so?

 

[novice_mechanic]

I bought the Frost version of Shrinker and stretcher, aside of the jaws clogging I noticed you only get a few goes at the shrinking/stretching before you have to anneal the steel and go again. I put it down to work hardening.

Bob

I came across this brand as well during my research phase of this whole SAGA. I chose the other over the Forst because of the price & they looked the same. Thank you for your input.

 

[Fairlane 66]

I found this on youtube as i wanted to get my Frost unit working better,hope this is of help to you.

Dave

 

[novice_mechanic]

I found this on youtube as i wanted to get my Frost unit working better,hope this is of help to you.

Dave

Thanks for your input on this. I saw similar clips on YouTube and tried it myself, inserting the sheet metal halfway, but to no avail; the jaws kept slipping on the sheet metal once engaged, preventing the Shrinking process from beginning.

 

[8ob]

what gauge of steel were you working with ?

Only 1mm Tom.

Bob

 

[8ob]

what gauge of steel were you working with ?

Only 1mm Tom.

Bob

Bolted both to a lump of angle so they can be held in an ordinary bench vice, saves faffing about swapping jaws.

 

[500e]

Are you giving the handle a hefty bump and fast
I have used them mainly on alloy, both jaws needed fettling before use.
Would think 1mm would be max
As @8ob said annealing may help

 

[Popcorn]

As said the jaws don't move enough and need a bit taking off the side so they can move further.
Seem to remember taking about one and a half mm of each jaw:

 

[bricol]

The clamp holding them in place kept moving on mine - welding washers over the slots to the screws kept them in place kept the jaws from sliding out under load.