casting

[dartman]

OK,I'm going to use a pressure pot for the first time.What pressure do I set it too and for how long?I am using the pvc method.I
will be using the casting craft resin.

 

[jttheclockman]

First and foremost safety is paramount when doing pressure. I hope you did your homework on preparing a pressure tank and you did not mention which one. Never ever go 20 lbs close to cut off. In other words if tank is rated for 80 never go over 60. I cast at 50 lbs but have been doing it for awhile and have a proven tank. That resin you chose will kick very fast and heats more than most resins so it will probably be done in a few hours. I like to leave my blanks 24 hours but I use epoxy resins that are very slow curing and also Silmar that is slower than your resin. Make sure blowoff valve is intact and when tightening the thumb knobs alternate the sequence. Like you would putting a tire on a car.

 

[Kenny Durrant]

As mentioned before you need to know the max psi on your pot. Mine are 80lbs and I set the actual psi at 55 lbs. There are some that max at 60 lbs and lower. I do know some casters use 35 lbs and some 60 and up. As far as I go 55psi is a good number and well below my max pressure. Don't press your luck because it can turn into a bomb if your not careful. The only Casting Craft Resin I'm aware of is a polyester resin. I use 3-4 drops per ounce and leave under pressure for 12 hours.

 

[howsitwork]

I use 50psi and leave overnight with aluminite clear cast . Pot pressure max is 90 on mine . No experience of that resin I'm afraid but use release spray on the mould or extraction becomes a whole new challenge

 

[dartman]

Thanks guys,I am using a new harbor freight pot and the max psi is 60so I will go with 40lbs or will 50lbs be ok? Will the humidity
outside have any effect on the resin like it will with paint?

 

[dartman]

I use 50psi and leave overnight with aluminite clear cast . Pot pressure max is 90 on mine . No experience of that resin I'm afraid but use release spray on the mould or extraction becomes a whole new challenge

I have cast in pvc tubes before and found the resin shrinks and I just knock them out real easy.Will using pressure change that? edit I just thought about that and of course it would,under pressure it will solid to the tube am I correct? Thanks for bringing
up and what can I use for mold release?

 

[howsitwork]

No the resin will still shrink as that's a physical reaction caused by the chemical curing.Pressure just stops air bubbles forming its doesn't stop the physical change .

I got some specific release agent but I gather PAM spray ( some sort of cooking oil spray you can get in USA )works too? Ask those like JohnT for the best ones available over there. I shattered one of my first blanks getting it out as hadn't used enough WD40 spray on the mould.

Went oit and got the specific mould release after that, big improvement and lesson learned.

Have fun

 

[jttheclockman]

I do not use mold release because I do vertical casting but use clear plastic tubes that become part of the blank and get turned away when turning to size. To me so much easier than those pvc pipes but that is just my method which I have been doing for many years. Learned that from CaptG for those who remember him. Example

 

[howsitwork]

Nice and easier than extracting !

Is that braided cable ( metal) or fabric type? and do,you stick to the tubes first or impregnate to adhere it?

 

[jttheclockman]

Nice and easier than extracting !

Is that braided cable ( metal) or fabric type? and do,you stick to the tubes first or impregnate to adhere it?

That is stainless steel braiding. I cast in silmar41 so I adhere the braiding to the tube with the same resin.

 

[erichardson]

I cast vertical in pvc. I use Stoners mold release and Alumilite resin. Releases with no problem.

 

[howsitwork]

That is stainless steel braiding. I cast in silmar41 so I adhere the braiding to the tube with the same resin.

thanks John.

very interesting idea . Two more questions how do you be cut it to length in the first place?
I find cable cutters always fray the ends a bit . also what sort of trimmer do you use to square the ends so neatly please? I am assuming a carbide one for wear resistance? Preassure cast or is silmar41 slow curing so bubbles are less of an issue? Sorry just realised 3 question not 2

 

[jttheclockman]

Hello Ian I did not even know this thread was opened again but will try to answer a few of your questions. These blanks I shown were some of my older versions because there were changes I made due to new material being available. When I was making those back then the braiding was a tighter weave and tougher to work.I did use a carbide trimmer to square the ends and it worked well and still does. But I use a 4 cutter carbide cutter. Will not rip or grab like the ones today. They were made by a member here years ago.

Now this may get lengthy and I will add some links if I can.

Now fast forward to recently, Home Depot and other plumbing vendors carry flexible hoses and have a stainless braiding cover on it. They were used for wash machines but have gotten into other areas such as sinks and toilets connections. https://www.homedepot.com/b/Plumbin...Stainless/N-5yc1vZbqjnZ2bcueaZ1z138lgZ1z13d4d This stuff is lighter but still stainless steel and is not such a tight weave so easier to work. Back then I cut the weave with a pair of tin snips and still do today. But today I sand the ends down on the lathe as I do with all my blanks. But I use paper made to sand metals. https://www.amazon.com/Norton-23610-Long-Longboard-Sandpaper/dp/B000FKLWXE Now To get to that point I have shown how I cast my braiding materials before but will include a photo or two. After I make up the tube I cut exxcess off with tin snips. and to trim real close to the tube I found these snips to be the perfect ones for us pen makers to cut many materials and they do cut this stainless easily. I use it to cut all my braiding and got the idea from Turners Warehouse. Got them on Amazon https://www.amazon.com/gp/product/B0006O5KEG/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1 After I get reall close to tube I now cast in Silmar41 resin. I do use pressure pot. Silmar needs that. Take out sand down close to tube and then put on lathe to finish sanding. Regualr sand paper will not cut the stainless so I use the blue stuff. When I get down to tube I put 150 grit wood paper on to polish the ends some. This just sand the resin. Turn as always.

I am sorry I do not take photos of every pen I make so I do not have the latest stainless pen but if you want to see comparison I think I can dig it up and shoot a photo. Otherwise here is the rack I was talking about and you see how I adhere my braiding till dry. There is a photo of 4 braided pens I make Brass, stainless, copper and chrome. I do a couple others but again no photos. Then there is a stainless pen from the old style stuff. The new stuff from Home Depot has a coating on it and you can see easily the different weave. Hope this helps and any further question I will be happy to answer.

 

[howsitwork]

John

thank you so much for taking the time and considerable effort to explain this to me. I have some copper braided cable i'd like to try out. I really appreciate that reply

By way of a thank you can I highly recommend J flex cloth backed abrasive made by hermes , RB406 was developed for sanding stainless steel and is washable . I was told of it 20 years ago and it's damn good stuff.

Currently I'm playing with some new resin and a couple of bowl blanks but braided pens are on the" wish list".

Ian

 

[jttheclockman]

Copper is some easier material to work with. Here is a couple I did not long ago that is stainless and brass woven in. looks really sharp up close. I did the gear pen for a friend. He loved it. If I can help with anything let me know.

 

[PostalBob]

As everyone have or thought about casting braided rope.. Keep telling myself going to do it one day.. Love them all

 

[jttheclockman]

As everyone have or thought about casting braided rope.. Keep telling myself going to do it one day.. Love them all

Probably if it was thought off it was cast. Here is my attempts as double weave nylon braided boat rope. In different colors.

I probably teased this idea here when I posted some blanks I have on my work bench for future pens. Some I completed and other not. I could have used those ropes but went with this other plan of trying to match a colored acrylic cap for them with the same angled segmented insert.

 

[howsitwork]

John

Im fascinated yet again. So we're those ropes nylon cored and you've removed that core and replaced with the tubes? Did you need to degrease the sheath before resin impregnation? I'm guessing pressure pot to ensure total saturation and removal of bubbles?

Secondly the idea of diamond or other insets attached to the tubes then resin. Simple but I'd never considered it . For better adhesion rounding the inside contact surface of the inset before attaching it to give bigger surface grip area ?

So many new ideas but today is box turning day , Once I've raked the leaves from the lawn again, three days on the trot they've needed raking up and composting. Oh well keeps me fit ! I'd just cleared this area then the wind blew . today twice as man6 but the trees are looking bald now ( know the feeling?.)

 

[jttheclockman]

John

Im fascinated yet again. So we're those ropes nylon cored and you've removed that core and replaced with the tubes? Did you need to degrease the sheath before resin impregnation? I'm guessing pressure pot to ensure total saturation and removal of bubbles?

Secondly the idea of diamond or other insets attached to the tubes then resin. Simple but I'd never considered it . For better adhesion rounding the inside contact surface of the inset before attaching it to give bigger surface grip area ?

So many new ideas but today is box turning day , Once I've raked the leaves from the lawn again, three days on the trot they've needed raking up and composting. Oh well keeps me fit ! I'd just cleared this area then the wind blew . today twice as man6 but the trees are looking bald now ( know the feeling?.)

Lets start here in red. Yes I removed the white inner core and it left the colored braiding. What got me started was seeing a rope in Home Depot (gold and white) as I was looking for some chain and that had to be the department and of course the casting part of my brain clicked in and that is where it started. Now the rope was too large even without the core so went on line to find other colors and found these and a few others which I have not cast yet. No need to do anything to the rope and the tube just rough up. I use silmar41. Now what I did find is you need to use a color preservative such as those used in thread tying for fishing poles to keep the colors vibrant or else the resin turns them too dark and muddies the whites with the color. Yes on the pressure pot. I always use pressure when casting. Even when using epoxy resins.

Now the blue question. I did these because there was a run of diamond making segmented blanks being shown here. I thought I would add a different approach to that theme. These are mother of pearl inlays used in pool cues and pool tables. Yes I took my dremel tool with a small round sander and contoured the backs to fit the tube better and give a better glue surface. If you do not do that you can turn away the edges of the diamonds. These were carefully laid out in a pattern around a sierra tube and I have included photos of the finished pens which I have shown here before. Glued on with med CA to give me time to adjust. Let gas off and these I cast with epoxy resin and turned and polished. I mixed my own colors for these. Epoxy resins stick much better to objects like this. I use that for watch part pens too.

 

[howsitwork]

Brilliant John

again I am amazed at your skill and inginuity . I know what you mean about " clicking in" . Indeed when ever I gaze upon the engineering tools section of ebay I am often tempted. I find having things sent to work so as not to " inconvenience SWMBO " with home delivery helps maintain a peaceful working environment.

Just a thought for you , I started using these drills last year and find they give a much better result than traditional lip and spur wood bits. Ok you still have to watc( it for blow out at t( end of blanks but they don't tend to grab and split blanks.

Havent found silmar 31 resin over here yet so might try out some others for size. I will report back when I do ( but at current rate of progress might be a while so don't hold your breath ( puce ain't a good look ).
Just knocked up this for a friends wedding anniversary, sanding it was a challenge.

stay safe and inspirational !

Ian

 

[jttheclockman]

Thanks Ian. By the way the resin is Silmar41 but most resin will work. As I said I find myself using alot of epoxy resin for things I have been doing lately. Have 4 blanks that need to be cast and will get those done soon. Working on 5 blanks now with some segmenting involved. Hope they work out. Then I have about another 6 blanks that are just started and need lots of thought yet. I think after I get these done I have a couple scrollsaw projects I want to complete. After seeing your heart, one of them involves a scrolled heart shape that I have been wanting to do since last year. If I would have had shows I probably would have gotten it done but since no shows this year I basically stuck with pens. Anyway nice work and good luck.