Welding challenge

[phaxtris]

your question is more "polyester resin vs epoxy resin", the can tire stuff is polyester, it works, but im sure something by total boat is "better"

polyester resin is easier to work with and cheaper than epoxy, polyester resin is the most popular type of resin used for fiberglass type projects, by a long shot....think boats

epoxy cant be used with fiberglass strand matt, you need to use the woven style of mat, weather that be fiberglass, carbon fiber or something fancier. Woven matt is more difficult to use around relatively tight radiuses and complex shapes.

if you want the lightest part with some kind of resin, carbon fiber and epoxy, i dont know if it would beat out riveted 20g (weight wise), it would be a lot more difficult thats for sure.

I have done a fair number of fiberglass projects, from speaker enclosures, transom/boat repairs, to airplane parts, there is a learning curve. Working with any kind of resin/matt arrangement has tricks and takes some skill. You need to make forms/plugs/molds, mix resin, fight with matt, apply resin, maybe 2 or more layers, 12-24hrs per layer...

Your doing good with the welding, i wouldn't give up on that, i just wouldn't use welding for this particular part (not because of skill, its just not the best application), there will be other things to weld, so keep at it

 

[PeterT]

I would add to what @phaxtris mentioned. There is also vinylester which is similar to polyester in terms of its viscosity, catalyst % and cure properties, but its better grade stuff. Kind of in-between properties of polyester & epoxy. I would not say polyester resins are necessarily easier to work vs epoxy but it all depends on the application. If you are saturating heavy mat or doing resin infusion then yes. But they are sensitive to tiny discrepancies catalyst which is only 2% by volume. Epoxy's are much higher A&B ratios like 1:3 1:1... so easier to get correct by weight or volume. Epoxy's also vary significantly by application type, choosing the wrong one has consequences. Glassing a boat has different requirements than a structural part or something seeing temperature cycles. Also pay attention to the nature of hydrocarbons if that's what they are holding. Many which are gasoline rated don't do well with ethanol blends & certain kinds of oils don't play nice together.

 

[ShawnR]

Thanks again for the input everyone!

I know there are a ton of videos on line to address welding of all kinds, many well known due to their quality.

I stumbled across this series from the Everlast site. It has not come up often in my searches, but I think this guy does a great job. I watched the one on Aluminum TIG welding for Beginners, found it good. But this one demonstrated to me 3 of the 4 things I noted I did, despite being told not to do it. Sometimes a picture is worth more than a thousand lashes with a wet noodle, I guess. I think my gas is good, but the last three, I have seen in my attempts, and did not realize what I was doing to cause them. The balance I think I have addressed, but probably still have too much cleaning as my tungsten does have a small ball on it.

I will report back....

 

[phaxtris]

there are 2 things in your second video that i would say are "off", the comments on arc length, and balance. The range of work and experience he has must be small to make those comments. I believe he is probably mostly self taught and commenting from the experience he has (looks to be he fab's valve covers, oil pans, and other automotive related items).

Both arc length and balance are determinate by the project, hotter bigger welds require more arc length than smaller colder more precise welds, dirtier material requires more balance than clean material (think casting's). Both of those things are just tools in the tool box to get the desired outcome.

Trying to lean with a 1/16-3/32 arc length is not easy. The general rule is 1/8-1/4, tighter and further as the job demands, sometimes you are going to want a very small weld on very thin material, then your arc length with tighten up (possibly down to 1/16), other times you need a wider, hotter weld, the arc length may come out even past 1/4 depending on your amperage and gas coverage. If your weld is to wide, or your having gas coverage issues, then yes, you are to far, if you are constantly contaminating your tungsten you're probably to close (at least for your current skill level)

The comment about not needing to see your weld is laughable, if you cannot see what is being melted you cannot ensure a quality weld. He may be getting away with that because it appears he makes hundreds of the same type of part with the same joints, so from experience he knows what the front of the puddle should look like with proper fusion, but this is not good advice, no one who welds for a living will tell you that you dont need to see the weld, that is the first thing you need.

And balance, for general work with new material you are looking for more of the penetration (EN) portion of the weld, but the reason your tungsten could be disappearing into the cup could be two fold, to much amperage, or to much cleaning. You may be running to hot for that size of tungsten, or to much balance for that size of tungsten. If just the tip balling a little that is ok, welding with a ball used to be how aluminum tig was done and taught, but if its completely disappearing, its time to look at the balance or what size of tungsten your running (for the amperage you are using).

There is a reason you can vary the EN-EP percentage, dirty material (poor quality aluminum, castings). Say you find yourself repairing a wheel, or some other casting, you are going to need to run much more (maybe even max for you machine) EP, the EP portion of the wave helps draw out the impurities from within the weld puddle and make the repair possible, you will of course need to run a much larger tungsten. Generally speaking you want to run as much EN as you can get away with, but that is not always 30%