HB (Hansen Boards)

Document your personal work here. Show photos, movies, and share your secrets.

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heke
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Post by heke »

Akiwi wrote:Was very busy the last few days.
I got some new aluminium to make my mould. This time I used 3mm. Holy cow it is difficult to bend. I was happy my bender was able to handle the weight I had to use.
What is radius you have in your Aluminium mould tip & tail? I have find a work shop that can make me mould, but I need to make a drawing; I have autocad.
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Akiwi
Posts: 370
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Location: Olching (Near Munich) Germany

Post by Akiwi »

heke wrote:
Akiwi wrote:Was very busy the last few days.
I got some new aluminium to make my mould. This time I used 3mm. Holy cow it is difficult to bend. I was happy my bender was able to handle the weight I had to use.
What is radius you have in your Aluminium mould tip & tail? I have find a work shop that can make me mould, but I need to make a drawing; I have autocad.
No idea, I bent it by hand untill it looked about right.
I am nobody. Nobody's perfect, so I must be perfect.
heke
Posts: 113
Joined: Sun Dec 06, 2015 9:44 am
Location: Europe

Post by heke »

Akiwi wrote:
heke wrote:
Akiwi wrote:Was very busy the last few days.
I got some new aluminium to make my mould. This time I used 3mm. Holy cow it is difficult to bend. I was happy my bender was able to handle the weight I had to use.
What is radius you have in your Aluminium mould tip & tail? I have find a work shop that can make me mould, but I need to make a drawing; I have autocad.
No idea, I bent it by hand untill it looked about right.
Thanks, ok, I will measure from my skies..
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Akiwi
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Location: Olching (Near Munich) Germany

Post by Akiwi »

I am building a new pair of skis as a birthday preasent for my Mum.
Tried a few different things in this set.

The core is a combination of vertical laminated Ash and Paulownia to try to keep the weight down.

The ash strips are 3 cm thick which is probably too much, as after cutting out the core, there wasn't much Paulownia left.

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Akiwi
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Location: Olching (Near Munich) Germany

Post by Akiwi »

Next job was cutting everything out and beveling the edges, Rebbit, Glue on the edges etc.

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I tried something new with the pressing.
Tried using a cap construction with veneer, and a matt top sheet.

I think it was a big mistake!
As I didn't use any fleece or something there appears to be nowhere for the excess epoxy to flow..
I was worried about if the top sheet would laminate so put in some extra epoxy.
Was a hell of a job trying to get air bubbles out too.
We will see when it dries.

Image

Image
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Akiwi
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Location: Olching (Near Munich) Germany

Post by Akiwi »

DAMN!
I did a relatively big Stuff Up.
I took the skis out and my worries were confirmed.
Actually I made a couple of mistakes.

Error 1.
The Plastic top-sheet is a problem in vacuum presses when doing top-cap skis as the resin does not have anywhere to escape.
The vacuum presses the top-sheet down onto the aluminium of the form, and prevents any resin or air bubbles from getting out.
Result are heavy skis with bumps and waves on the surface where excess resin formed.
Also ugly bubbles under the clear plastic top sheet.
Next time I will include something around the skis to like fleece or breather net to allow excess resin and bubbles to flow out.
Error 2.
I am so f..ing stupid. I put the clear top sheet on upside down!!
I thought that I had got the wrong stuff as it was matt on both sides, So I assumed they had sent me matt instead of glossy. I tried to peel something off, but obviously didn't try hard enough.

The good thing is, I could peel the entire top sheet off, and now I can sand the air bubbles out..
Not sure if the skis are useable... I'll keep them as a ski instructing pair for my kids.

I am going to make a new pair with the following corrections.

1. I will press to the veneer layer using peel ply and add some fleece or something to the table around the skis to allow excess resin bleeding. Therefore I can be sure that all the excess epoxy is removed.

2. I will add the glossy top sheet as a seperate step.

3. I will use bubble inhibitor in my resin to help reduce bubbles forning.

4. I will also make sure that the top sheet isn't pressed flat to the table.

Snowed today, so good for taking photos of skis!!
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satch
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Joined: Wed Mar 28, 2012 5:38 pm

Post by satch »

That's a pity. The picture looks pretty good.

If i were you, I wouldn't use a top sheet over veneer. At least not in a cap construction ski.
There is no way the air and excess resin inside the layup can escape from under the top sheet.
If you are using the anti foaming agent as sold by skibaumarkt.de you will likely have even bigger bubbles under you topsheet. It willreduce the tiny air bubbles inside your layup. But as mentioned the gas has nowhere to go so it will probably end up directly under your top sheet.
Why don't you just impregnate the veneer with some extra resin?
heke
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Post by heke »

Well..you learn something.i just put the foil with small holes ( sold by skibaumarkt) and fleese. The surface is nice. I put also epoxy on top of veneer but it I need to try something else next time, epoxy is not hard enough. I have heard that le toking oil will make hard surface. I will try it to my next pair.

It was pity.. Your skies looks nice
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Akiwi
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Location: Olching (Near Munich) Germany

Post by Akiwi »

Thanks guys,
It's all a learning experience, and hopefully we can learn from our mistakes.

I am impregnating the veneer fully, but it is not hard enough to handle the sharp edges. So I thought I would try something different.

I think for the replacement ones I will use my old tried and tested 2k car clearcoat. I'll experiment with the topsheet on a pair of skis for me or my family.. I'll let you know how it goes.

With regards to the bubble remover.. I think I will mix it in, and leave it for 5 minutes or so to get rid of the air before using it under the topsheet.
I am nobody. Nobody's perfect, so I must be perfect.
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Akiwi
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Location: Olching (Near Munich) Germany

Post by Akiwi »

Ok, at last I have the replacement skis in the press.
Why does everything seem to take 50 times longer than you expect!!!

I made the Ash stringers thinner .. 2 cm instead of 3 cm. This leaves more room for Palownia to help keep the skis light.

I also went a bit overboard this time ensuring that the vacuum got everyehere, and lay down mesh to allow any excess epoxy to come out..
Working hard to keep these skis nice and light.

Image
I am nobody. Nobody's perfect, so I must be perfect.
heke
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Location: Europe

Post by heke »

Hope its better this time. I don't like to work under pressure at hobby. Well my daughter wants to have pink skies. I dont know how to make pink top sheet.
skidesmond
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Post by skidesmond »

Use pink fabric for a top sheet. Look for a light weight cotton material.
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Akiwi
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Location: Olching (Near Munich) Germany

Post by Akiwi »

I weighed them, They are 1.23 kilos and 1.31 kilos.. That is 2.7 and 2.88 pounds. I am happy with that.
Did a bit of a painting session tonight.
2 Mini cruisers, a Longboard and 2 pairs of skis.
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Akiwi
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Location: Olching (Near Munich) Germany

Post by Akiwi »

New Season and new Projects.
Just finished a longboard for a customer.. I am very happy with the result.
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Thanks to Dan Graff I have lots of new toys in my workshop. I spent about 2 weeks installing a dust extration system that goes al around the shop, and includes intakes on the floor where you can sweep stuff into it, and it just dissapears!! Wonderfull.

As I got a planner, I decided to build a Crib for this method.
Thanks to Michi and Hannes from Bakery Snowboards, I got a nice piece of Pre drilled MDF, so I built around that.

Bought a piece of Multiplex that fits in the Planner, countersunk the inserts to match the holed in the upper MDF

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Next I cut a bunch of fillers ranging from 1mm to 10mm which I can place between the layers to make my profile.
For 0.5 mm I found 5 layers of painters Masking tape is exactly 5.. thick.

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Screwed it all together.

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Checked the profile on the side, and it came out perfectly.
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I got a bunch of skateboard topsheet for free from my Skateboard parts supplier. It was so ugly that noone wanted to buy it, so he gave it to me..
Stuck that on the top to hold the core in place.

Image
I am nobody. Nobody's perfect, so I must be perfect.
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Akiwi
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Joined: Thu Jan 15, 2015 7:48 am
Location: Olching (Near Munich) Germany

Post by Akiwi »

I started making a core out of Ash, but as I was having trouble cutting straight with the band saw, I decided to get one of the beautiful bamboo cores from the bakery guys. It is stunning!!

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I fed it through the planner. always only in 1 direction. meaning I profile the tip, then the tail, so there is no danger of the blades catching the wood, and breaking it.

I was very impressed at how accurately it came out. Approximately 0.2 or 0.3 mm tollerance. First try, I can probably tune that with experience.

It took me 45 minutes to do the first core.. Maybe I took too much off in the middle so it took longer.

Comparing to using the router..
Setting up the crib is easier.
There is much less risk of messing it up. With the Router it is very easy to slip or cut too deep in the wrong place.
there is much much much less mess. After using the router my workshop was knee deep in wood chips.
I think I took about the same amount of time... but if you add the time it takes to clean my workshop I would say the planer is faster.
Possibly took a long time as the bamboo is very hard. I could only take off about 0.1 to 0.2 mm per pass.
I am nobody. Nobody's perfect, so I must be perfect.
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