Warped sidepanel

[Peterman63]

Hi all,

The right side panel on my RF87 is warped and curved outwards.
Previous owner forced it in place with a lot of tie bands, causing multipel cracks in the gelcoat and edges. The inside of the panel is touching a crossmember way before the upper edge is aligned with the longitudinal tube, as shown in attached picture.
Any suggestions of how to repair and make the panel straght is highly appreciated.

/ Peter

[tlracer]

I had some success (with a seat) by 'stretching' it using wooden struts then a long time with gentle heat (I put it in the same room as our heating boiler!). This was with a quite new panel, however.

The side panels of the RF86 I have - which were the original parts - had been removed and stored flat for years so had gone very brittle and out of shape (like yours) so I had to replace these with new panels.

Universal Racing Services have the moulds but I'm not sure how such a gig panel could be shipped safely to prevent damage.

[Peterman63]

As this is probably the original panel, stretching it at slightly raised temperature could probably work over a long time.
I'm looking for a imminent repair since the racing season, thought postponed a few weeks due to pandemic reasons, and track testing is coming fast.

One idea i have is to make a few shallow long cuts on the inside, basically make slots in the fiberglass (but not thru gelcoat), bend it to shape and put layers of fibrglass on the inside.

Would the gelcoat accept that without cracking?

[JHerscher]

The gelcoat will likely crack.

I would try to grind the inside of the area thin and push into the desired shape and reglass. Grind an area about 20mm square and enlarge as necessary.

Do it in stages; you want to remove the least amount of glass possible and get the desired result.

Start by just taking off the first .05 mm of thickness and check. Then try another 0.5 mm and so on. Reglass with whatever it was originally made of, likely mat. Polyester resin.

I expect you only have about 3 mm thickness of glass layup to begin with, so take it easy.
Even then, the gelcoat may crack. It is very brittle.

[Gary_T]

I'd try a heat gun before a grinder.

You can get a fairly large area quite warm in ~20 minutes.

If you can - do it with it mostly mounted, and then pull/stretch/press/pry and hold it into the desired shape.

If you can't - get it warm, mount quickly, then re-warm as well as possible in place before trying to move it.

If that doesn't work, you've wasted an hour or two before you break out the grinder/fibreglass. I've never 'moved' a panel that big, but I have made fairly drastic changes in smaller parts.

Gary

[Bill Johnson 42]

I had the same issue with my VD side panels and had no luck. I locked the side panels down and exaggerated the "warp" going the other direction. Put a propane heater underneath of it for 24 hours that was hot enough to make me worry about melting the paint and tried it multiple times. Made absolutely no difference.

I have read in other places heat works, maybe over a week or longer may yield different results.

[problemchild]

I would try to grind the inside of the area thin and push into the desired shape and reglass. Grind an area about 20mm square and enlarge as necessary.

Better to spend $25 on materials, and 2 hours of time, to complete the task ...... than spend days and weeks with heaters and heat guns to find out you need to reglass anyway. Inserting the smallest rib (wood, plastic, aluminum tube) across the panel will help keep it straight,

[Jerry Kehoe]

I have had good results using a heat gun or other source to soften the panel, put it into the position you want then while hot take a cold wet rag to the panel. This seems to lock it into position. Merely heating it into position will do nothing, the cold wet rag is the key.

[Peterman63]

Thanks for the advices, guys!
The coming weekend will be quality time in the workshop, so expect an update of the results of my efforts on monday at the latest.
Happy Easter!

[Peterman63]

Did the heating procedure with various success. Clamped on some 2" x 3" wood to straight the panel somewhat and slowly heated the outside first to soften the gelcoat. The panel made some cracking noices so it did loose some tensions. Not sure how soft it got, but the gelcoat did get a slight "bubbly" surface...
Continued with the inside and spend o lot of time heating it, increasing the bending and adding a few clamps to overbend it a little.
Left it to cool for a hour. The panel is now straight (ish) and fits so much better!
Did the same to the rear lower panels but without heating the gelcoat, so no bubbly surface there.
Seams like heating the inside with some creative clamping, increasing the bending in steps and also "overbending" (as it will spring back a little) is the way to go.