Help with pressurized air hose

[Morten Petersen]

I have a problem...im piling up laminats but im hesitant to make more bows using clamps and rubber bands (somehow I get crappy gluelines...no glue failures yet tho). Now I have finally aquired 4 yards of hose from a friend who works at a firedepartment.

But how do I seal the ends and what kind of valve will do, and how do I instal it (I have a 12 bar compressor)?

Cheers

[Robertfishes]

I would buy new hose and plugs from Binghams, they will both be of the correct size..I  would hate for you to have a hose or plug failure and waste $100 of materials.

[Morten Petersen]

Thanks Robert
But I kind of insist on making these things myself...if at all possible. I can only truely appreciate a bow if I feel I have made myself;-)

If its very difficult to make a hose then ill have to considder alternatives for sure:-/

Oh...I rarely pay for materials so dont worry about that;-). Im fortunat enough to have acces to alot of fine materiales:-)

Cheers

[Swissbow]

Have you figured out yet the reason you got bad gluelines. Maybe it's not an issue of how you apply pressure but a design problem like the radiuses on the fade out to narrow or to steep. Or even something else. It can be very frustrating if you do a lot of work only to find out that you have made a wrong assumption.
Guess how I found out that one !!!

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Andy

[Morten Petersen]

Two reasons are obvious:
-Lack of enough C-clamps (I have only 14), and not enough pressure using rubberbands.
-Badly planed lams (this I have solved).

Also im using white carpenters glue (wooden lams only)....which maked imperfections more visible than when using epoxy!

So, I was offered this hose and thought...well, how hard can be to make?

If it proves too hard then im of to buy more epoxy and C-clamps...the air hose method just seemed appealing.

Ill try and make a hose regardless (have no other use for it) and will make a post if im succesfull;-)

Cheers

[Swissbow]

I'm getting very clean glue lines with the rubber band method. You can easily apply enough pressure with this method. If not then maybe the lams and riser ( fade outs ) don't fit good enough. You don't need an incredible big amount of pressure to get good glue lines. Also make sure that the gluing sufaces are roughed up and cleaned before glue up. Since I'm building glass laminated bows I only use epoxy and I have very good results with it. The type of epoxy I'm using is very liquid so it penetrates good into the wood and the rest is squeezed out when applying pressure.

Do you have any pictures of your glue lines ?

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Andy

[Morten Petersen]

No...but maybe I should make some pics.

One of my problems might be that I use rather thick lams 2-3 pcs (bamboo/core/jatoba and sometimes I skip the core) in a rather agressiv ref/def mould...rubberbands simply wont hold down such a stiff ansemble!

Again...I can work around this with more and thinner lams (harder to control the setup then) or a less agressiv style bow mould.

There are alternatives I know (lots of variables to tweek;-)....but Im partial to give the presure hose a shot now that I have one.

Btw...atm a riser is not even part of the equation, I plan to glue that on afterwards.

Cheers

[Trux Turning]

Here is how I made the plugs for my hoses- I tapped a screw in air valve into the cap, on the cap, pipe and valve threads I used high temp sealant and hose clamps- this has held up to 5-6 years of use.
 
 

[Mike Most]

http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=004337

Just for saftety sake read the above posted on the 13th of Oct.

Regards

Mike

[Morten Petersen]

Ok...here is what I did:

I found a spray can that fitted perfectly inside the hose. I cut it in half and plugged each half with a short wooden shaft (to handle the pressure from the constricting bands).
I drilled a hole in the shaft to enter the half containing the spraycan nozzle, though which the small tube that connects the nozzle with the bottom of the can could go.

Here is a picture:
 

I can fill the hose by connecting the nozzle of my compressors dust blower gun (takes 10 sec to fill to 130 psi). I have used no sealant...just bands, can and two shafts...and it droped from 130 to 115 psi over 24 hours...good enough for my purpose;-)

I have no idea how durable this will be, or if it will hold up to the warmth of a heat box (I wont use it for that). Biggest drawback...it takes 3-5 min to empty though that small nozzle (I plug on the original spray can nozzle for that).

Cheers