How do you tell IF a repair has been done?

[jonnyques]

Hi before everyone says just look at it... let me explain. How can you tell if you are looking at a old repair that has gone bad? I have seen some brakes that look like the need doing but looking at the pit it looks yellow and flakes out. Some appear like the resin has seperated inside and now look black. I guess a true way is to put the bridge on and try them. The reason I ask is I saw one today that I would have sworn needed filling. After poking at the pit (yellow and flaky) it reveiled a drill hole. I decided to leave it alone. Just wondering if there is anything you guess look for or do when looking at what may be a old repair?
Thanks All

[gold star wsr]

Often the signs are pretty clear, as seemed to be the case with the one you describe. Sometimes you just dont know until you start to work on them. Usually, though, if you pick at the center with your probe, you wll be able to feel the resin in the pit. Resin feels and sounds different than glass when you scratch it with your probe. All is not lost, though, if it is an old repair, but you do have to work harder and usually spend more time filling them than you would with one that has not been previously worked on. I try to drill out as much of the old resin as possible, then I tap a new break to open the channels that the resin is now blocking. Then proceed as with any repair, setting up the bridge and injecting the resin etc. Frankly, I hate doing reworks, but sometimes I get sucked into doing them, and when I do, I try to do the best I can with them. I almost always use the thinest resin on reworks, just to be sure it gets to the ends of all the legs.

[screenman]

if you are going to have a go at repairing someone elses mistake always make sure to let the customer know before you start that it has been done before and is not usualy redoable. ( make sure they are listening)

This sets them up with a lower expectation. Then if you do improve it they are normaly well pleased.

I do a lot of these and agree with the previous post as to how to do them. The only thing I would add is that on badly filled bullseyes I will clean the old pit finish out and use my blow torch and get the repair really hot this seems to release tbe old resin and usualy gives me a almost original damage to get one with.

[Dave M]

My advise....don't try to redo an old repair. It's just not worth your time, plus you risk making it worse. Tell your customer it's been repaired and that you can't make an improvement. Move on to your next job.

Screenman,
I see you have 16 plus years in the business but geesh, telling a newbie to heat the old repair with a torch! I can't believe you suggested that one. It may work for you, which is fantastic, but for a new tech?

[gold star wsr]

Just like any other type of repair, you can practice reworks too. Get yourself a scrap windshield and do a number of incomplete repairs. Then
rework them. You'll get the hang of it after a while. Some really should not be attempted, but to say reworks can never be done is not correct. But it does take more time and you do have to know what you are doing to get satisfactory results. It's a judgment call whether you want to do them or not. I recently did a rework on one of my own repairs Fortunately, the customer was a good friend. In fact, she appreciated that I noticed that it wasnt dont right, and was happy that I corrected it before it started running.

[gold star wsr]

PS, I also would be very careful with the heat. Do a lot of testing on your practice windshield and see how much heat you need to actually melt the old resin without also damaging the laminate or cracking the glass.

[GlassStarz]

If you cant tell by looking at it (and you should be able to if you are working in this buisness for more than a couple weeks this isnt ment to be a slam you will find after you have seen a couple they will jump out at you imeadiatly in most cases) take your awl and scratch the area where the pit will be if its softer than the glass its resin and has ben done before. You can clean up an old repair that has air pockets in them by drilling to the pocket these are the only old repairs I will touch other than filling pit where the pf may have fallen out.

[jonnyques]

I guess one thing I should ask is, does a pit (the glass) ever discolor because of the elements? Some of the brakes I see, have a discolored (yellowed) pit. This makes me think it has been done. When you look at the amount of visiable damage still present, I then think theres no way it could have been repaired that badly the first time. It could be possible that the damage has increased since the first repair. Thanks again for the replys

[Delta Kits]

Yellowed pits typically mean it has been repaired with bad pit resin.

[screenman]

I see doing old repairs again as another source of income and also a way to show how good I am at this job.

You will note the way I sell this repair I hope.

As for telling a newbie to use heat I do not have a problem wiht this at all it is one of the first things I taught myself. If you do not try then you will not learn. Remeber because of the way I sell this service the customer is not expecting me to be able to repair it.

I am sure there is a lot of you out there who earn more money and have been in this trade longer but surely am I to be shouted at for giving my opinion when asked. I will quite happily take my knowledge elsewhere if it upsets people.