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I have a question about tacking a joint before building the fillet...
I tack the joint while the tubes are in the jig, then move it to my Park stand to finish the joint.
This leads to my question: when I tack the joint do I just quickly heat up a couple small spots and tack them, or should I be worried about heating the entire joint like when I'm laying a fillet?
What do you do?
Most feel that tacking is a spot joining thing. Done on the centerline of the frame and maybe only a .25" long a fill (along the tubes' contact). This allows one to do an aligning of the frame with minimal tube/joint interface distortions/gaps. Then a full brazing off the jig is the usual next step.
By fully brazing the joint'circumferencece you pretty much lock up that joint's alignment. Making changes after this involves twisting the tubes and not shifting the joints.
When I tack I get in real close, tack and pull out in as little time as I can. The majority of the joint is not brought up to temp. When i go to the fillet stage I flow the joint fully (working away from the tacks on both sides) before the build up step. I know others do both the flow and fillet in a single step. You have to find wworkswors for you. Andy.
Good question and I'm really curious to hear what others do. From the few fillets I've laid down on my flat plate jig, I just place a small tack on the centerline like Andy said. Then I go to the Park stand to flow the entire circumference of the tube. Then I do the full fillet, which consists of my doing the fillet in quarters.
An extra question to throw in.. Do you re-clean/prep the joints after the tack, or do you go to town on the fillet after alignment is dialed in?
Thanks for all the responses so far. And seankanary, I was going to ask that same question!
Once the joint is cooled, I just reflux and go back at it.Quote:
Originally Posted by seankanary
I just tack with a little bit of powder flux, then put all the paste flux on once it's out of the jig and on the workstand.
Attachment 56091The faster you can tack, the better you are.
Tacking is an art.
- Garro.
Some things to think about:
- How repeatable/ accurate is your mitering?
- Your fixture?
-What are you asking a tack to do in your build sequence? In your brazing sequence?
It's a tool, but it doesn't work in isolation. I've arrived on tacking sequences that work as part of my overall process.
Garro,
Is the section of down tube covered by the seat tube brazed at all?
Yep. There is a fillet that goes the whole length of the hidden ST part.Quote:
Originally Posted by Todd Mosley
- Garro.
Quote:
Originally Posted by Todd Mosley
Just for clarity on my part........Todd, your question seems to imply to me that you think Garro's seat tube is mitered. Garro's response seems to indicate the DT is mitered. Either way, I guess the answer is the same in that the hidden part has a small fillet. Just making sure I'm not missing something in regards to which tube is mitered.Quote:
Originally Posted by steve garro
DT has the compound miter.Quote:
Originally Posted by Velo Wilco
- Garro.
Your miters are tight enough that I can't tell from the photo which one has the compound miterQuote:
Originally Posted by steve garro
Fuckin' A!Quote:
Originally Posted by Todd Mosley
Thanks, man - a man has to put his crazy somewhere.
That's what I'm actually doing more of right after this lemonaide.....
- Garro